Relational or Object-oriented
Hi everyone,
I'm just a novice in db design and have been given the task to design a db for our app. The app data consists of multiple Java node objects (as many as the user can think of, and needs to have) that, most of the time, have references to the parents and children (nodes). The main goal is to facilitate searching of objects (based on attributes) and object sharing. The objects are composite, meaning they contain links to others that contain links to many others.
I'm confused of which, relation or object oriented, databse is a better fit for the design. So far, several questions have popped up like:
1. To represent links (to other objects), which, an object id or a primary key, is better?
2. How to represent Java vector and hashtable in db?
3. If objects A and B link to C, after A and C are loaded, then if B is loaded, how do I know to share the copy of C (from A) instead of creating a new one?
Any help from you db experts, or if i can be pointed to the right direction, is greatly appreciated. And forgive me if I ask stupid questions.
Thanks,
You can use either a relational or an object-oriented database to store this sort of information. An object-oriented design may well be easier to build an object-oriented database if the goal is basically to use a database as a persistent bitbucket of objects that you will instantiate in an application server.
My preference, however, would be to use a relational database because that makes the data much more accessible to other applications. In most cases, if the data is valuable enough to want to write an application around, it is valuable enough to want to ensure that it survives any particular application. Relational databases are much better at this than are object databases, which necessarily enshrine a particular way of looking at the data.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC
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Can I develop a 100% Object Oriented DB with Oracle 11?
Hello!
I want to know if I can develop a 100% object oriented data base in Oracle 10g or 11? I have reed the "Oracle Database 11g The Complete Reference" chapter 41 "Advanced Object-
Oriented Concepts" and I still have the doubt if I can implement a database 100% object-oriented. I hope you can help me.
Thanks!>
I want to know if I can develop a 100% object oriented data base in Oracle 10g or 11?
>
The short answer is no.
See this AskTom blog for the long answer.
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1545206281987
It starts off with Tom saying
>
First off, in Oracle you would be considering pure relational versus Object RELATIONAL,
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Hi all, I feel confuse on object oriented.
Basic, I get change to developer some online form. I use java bean , Servlet, JSTL and Mysql. In my java bean I only have the attribute set and get pattern. I just wonder I put my delete , search and update action on Servlet , not in the java bean , is that means that Is not object oriented enough? How to improve it ?
thank you!Thank you for the reply, I did use some of the Spring in my Project, but only limit in flower control , such as simple spring + acegi , a lot of control still in servlet. I also try some other new stuff like display tag , but that only work on if your jsp page is out of the WEB-INF. I also go through some tutorials on JSF , but not time to figure out how JSF work with acegi yet.
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Object oriented programming in LabVIEW
Please send this message to everybody who has an opinion about this.
Please try to keep it short, but if you can't control yourselves, let
it all out!
I would like to have your opinions about the nature of Labview and it's
ability to support object oriented programming.
I have a couple of questions to fire the discussion.
1- Do you think that LV was built to support OO Programming?
2- Is OO the only way we have to support large applications, or is it
feasible to support it with a good dataflow architecture including all
the flowcharts and all the data definitions?
3- Is LV going to stay "dataflow" or is it going to become OO?
4- What would be the great benefits of turning LV to OO that we don't
already have w
ith the dataflow approach?
5- My opinion is that trying to implement OO in LabVIEW, is like trying
to
Thank you all for your time.
Sent via Deja.com
http://www.deja.com/> 1- Do you think that LV was built to support OO Programming?
LV was initially designed in 1983. OOP existed at that point,
but LV wasn't designed to be OO. It was designed to allow
engineers and researchers a simple language appropriate
for controlling their research labs from a computer.
> 2- Is OO the only way we have to support large applications, or is it
> feasible to support it with a good dataflow architecture including all
> the flowcharts and all the data definitions?
OO lends itself to large projects because it provides
abstraction, encapsulation, and organizes code into
modules that can more easily be implemented independent
of one another since they can be specified in finer
detail. Also, the compilers help to enforce the
specifications providing they can be encoded in the
interface between objects.
These OO principles were already a part of big projects
long before there were OO languages. It was just that
the language didn't necessarily have features which
supported it. Similarly, they can be a part of big
projects today despite the language being used.
LV 2 style globals, which as the name suggests were
in use long ago, encapsulate data with an interface.
They disallow arbitrary access to the data and can be
used to enforce correct access. With other functions
layered on top, you get a nice interface to stored data.
Functions and structs/clusters abstract away details.
Building a subVI that does an FFT means that for 99%
of the uses, you don't need any more information except
that this block performs an abstract mathematical function,
an FFT. The implementation can be completely changed
to speed it up or make it more accurate and your code
isn't affected. Its abstract definition still holds, so
your code still works.
There are other things that OO languages bring to the
table that LV, and GOOP don't yet offer. In my opinion,
a few more OO features can be added to LV to allow for
even larger projects in the future provided they are used
well.
Earlier posts pointed out that C++ doesn't guarantee that
a project will succeed. OO features are just another tool,
and the tool can be misused leading to a failed project.
This is true to LV, C, C++, and all other engineering tools.
The key is using the tools at hand to best solve the
problems we face. Not glorifying or blaming the tools for
the state of the project.
> 3- Is LV going to stay "dataflow" or is it going to become OO?
LV is dataflow to the core. The definition of what data
is flowing may be expanded, but it will still be data
flowing down wires from one node to another that accounts
for how the program executes.
One of the limitations of the current GOOP is that all
objects are dealt with by a reference. By adding
language features, objects could be made to flow down
the wire, just like strings and arrays, meaning that
branching a wire doesn't lead to side-effects,
and there is no need to dispose objects.
> 4- What would be the great benefits of turning LV to OO that we don't
> already have with the dataflow approach?
Remember when LV didn't have typedefs? It was easy for
a cluster datatype to change once a project was underway.
That usually led to lots of edits on other panels to get
them back in synch. Without the unbundle by name, you
then went through the diagrams fixing all of the bundlers
and unbundlers to have the right number of terminals.
Changing the order of the cluster was even worse since
the diagrams may not bread, they might just access the
wrong field instead.
In many respects, an object is just another step along the
same path. An object is a typedef that can have code
associated with it for access -- maybe like Array and
Cluster Tools. Some of the typedef contents might be
publicly accessable, like now, while other elements are
hidden, only available to the implementation of the
typedef. That would force the user to use your functions
to manipulate things rather than hacking away at the
typedef contents. As an example, a LV string is really
just a cluster of size and characters. Since the diagram
can only modify the string using the string functions, you
never get the size and characters out of synch. That is
until you take it into LV generated code, a DLL or CIN
where you have access to the inner fields.
A related problem is that current typedefs are transparent
to built-in LV functions. If your typedef is just some
numbers, LV will be happy to perform arithmetic on your
typedef. Maybe this is what you want, but if this doesn't
make sense on your typedef, then your left with adding a
Boolean or a string so that the arithmetic isn't allowed.
Ideally, you would be able to state that = makes sense, >
and < don't, + and - only operates on the first numeric, and
* is something that you implement yourself. There would be
some safeguards so that the user of your typedef, which
includes you, wouldn't accidentally mangle the typedef
contents.
These may not seem like much at first, but they allow for
much more abstraction and better encapsulation. Finally,
there is a technique called inheritance that allows for
similar objects to be acted on by common code in one
location, and by specific code in another location depending
on which type of object is actually there at runtime.
This of usually done today by switching out on some inner
tag and dealing with each type in its own diagram. This
works fine until projects get large and teams get large.
Inheritance is a different way of implementing the exact
same thing that usually works much better for bigger teams
and bigger projects.
> 5- My opinion is that trying to implement OO in LabVIEW, is like trying
> to
Is this a fill-in-the blank question? It is difficult today
because the LV language doesn't yet support OO very well.
Early C++ was implemented on top of C using just a bunch
of macros and the preprocessor to mangle the C++ back into
C so that it could be compiled and run. Debugging was
done on practically unreadable text that vaguely resembled
your original code. By comparison, GOOP actually looks
pretty good. It is written entirely on top of the current
LV language and makes clever use of things like datalog
refnums to make strict types.
Over time I think GOOP will mature, and like typedefs,
some users will come to rely on it in a big way.
Other users will hopefully not even notice that anything
changed. If their project grows in complexity and they
need another tool to manage things, it will be just
another feature that helps them to get useful things done.
Greg McKaskle -
Object Oriented Programming concepts
Hi Friends,
I need your help to understand the Object Oriented Programming concepts.
Please help me…
Thanks,
Fl4syedHi,
We can learn oops concepts very easily.Refering some books and search this concepts in some websites related to it.I think the author Robert lafore of oops is one of the best way to learn oops concepts. -
Object Oriented Programming features
Hello,
i want to know more about Object Oriented Programming features, actually i have basic knowledge on Polymorphism, abstraction, DataHidding, Encapsulation, Inheritance. I know the basic bookish definition of these, but can u people give me the definition in terms of java program or any definition which i can co relate with java program.
ex. Class is an example of encapsulation.
Thanks.RGEO wrote:Hello,
i want to know more about Object Oriented Programming features, actually i have basic knowledge on Polymorphism, abstraction, DataHidding, Encapsulation, Inheritance. I know the basic bookish definition of these, but can u people give me the definition in terms of java program or any definition which i can co relate with java program.
ex. Class is an example of encapsulation.
Thanks.see if we talk about encapsulation ----which means data hiding....now this can b expalined by the following example:
class Rect {
protected int len,br;
public void getdata()
len=14;
br=20;
public int area()
return len*br;
class box extends Rect
private int h;
public void getdata()
super.getdata();
h=56;
System.out.println("the height is :"+h);
public int volume()
return len*br*h;
{color:#ff0000}class inheritance
{color}
{color:#ff0000}public static void main(String[] args)
box obj=new box();
obj.getdata();
System.out.println("volume of box is:"+obj.volume());
}{color}
In the above example we are showing inheritance alongwith encapsulation and it goes like this:
we are able to view the result through main methods i.e. we call our method in main method with the help of objects....so we can say that whatever a user is showing he is showing through main method and not showing the logic because when we complie it then we are only shown the result and not the logic behind it.......This is known as encapsulation----showing relevant features and hiding rest all the things.
Edited by: Namrata.Kakkar on Jul 29, 2009 10:46 PM -
Object-oriented APEX. Best practices.
Hello,
in my company we are developing quite big application in Apex. At the beginning we saw Apex as a very developer friendly application, but now we have problem with it.
Our application has about 100 pages, most of them are not only reports but are also designed to edit and add new data. We are often using javascript and plsql procedures to handle collections and error processing. There are a lot of elements that are identical on several pages – not only processes, but also buttons, branches etc. – and when something changes, we must do the same operation on every page. Do you know any way to deal with it in better way?
Are there any “best practices” for APEX to make it more object-oriented? I know I can put e.g. plsql procedures as a function in database, but what about button functions etc.? Maybe I should name most important buttons in the same way and handle them using javascript?
Regards,
Przemek StaniszewskiHi Przemek,
I'm not an object oriented expert so I probably can't offer you too much in the way of advice here, I'm old school from relational theory, 3GL etc. But one of the things to remember is that Apex isn't one single language like Java where it is easier to maintain good object oriented practicies and even enforces and encourages. Apex is a collection of technologies such as Relational Design, SQL, PL/SQL, HTML and Javascript which are all held together by a declarative programming interface.
Although all these technologies have varying degrees of object orientism, they are all quite distinct technologies which work together well but don't really help each other in maintaining or enforcing OO good practices. I think it would be hard to reverse engineer an existing application, but with some thought, kowledge and advice from the right areas you should be able to put together some good design and coding standards which will serve you well going forward.
There are some documents and threads you should be able to find which will also help you, but also remember you are also dealing with some long established technologies such as Relation Database Design and SQL. Too often developers with skills in more recent languages get lost in the API front end and assume the database isn't really part of the application. You know, DBA stuff. For my money the database is the centre and the most important part of the application.
My two cents worth anyway.
Andre -
hello abapers,
am new to object oriented abap.cud u pls help me out in explaining me object oriented abap with examples.cud u also pls send me some links related to OO ABAP..
explanation wid suitable examples will b rewarded higher pints.
regards,
praveenHi,
please find the below material with examples,
reward points if helpful.
Public attributes
Public attributes are defined in the PUBLIC section and can be viewed and changed from outside the class. There is direct access to public attributes. As a general rule, as few public attributes should be defined as possible.
PUBLIC SECTION.
DATA: Counter type i.
Private attributes
Private attributes are defined in the PRIVATE section. The can only be viewes and changed from within the class. There is no direct access from outside the class.
PRIVATE SECTION.
DATA: name(25) TYPE c,
planetype LIKE saplane-planetyp,
Instance attributes
There exist one instance attribute for each instance of the class, thus they exist seperately for each object. Instance attributes are declared with the DATA keyword.
Static attributes
Static attributes exist only once for each class. The data are the same for all instances of the class, and can be used e.g. for instance counters. Static attributes are defined with the keyword CLASS-DATA.
PRIVATE SECTION.
CLASS-DATA: counter type i,
Public methods
Can called from outside the class
PUBLIC SECTION.
METHODS: set_attributes IMPORTING p_name(25) TYPE c,
p_planetype LIKE saplane-planetyp,
Private methods
Can only be called from inside the class. They are placed in the PRIVATE section of the class.
Constructor method
Implicitly, each class has an instance constructor method with the reserved name constructor and a static constructor method with the reserved name class_constructor.
The instance constructor is executed each time you create an object (instance) with the CREATE OBJECT statement, while the class constructor is executed exactly once before you first access a class.
The constructors are always present. However, to implement a constructor you must declare it explicitly with the METHODS or CLASS-METHODS statements. An instance constructor can have IMPORTING parameters and exceptions. You must pass all non-optional parameters when creating an object. Static constructors have no parameters.
Static constructor
The static constructor is always called CLASS_CONSTRUCTER, and is called autmatically before the clas is first accessed, that is before any of the following actions are executed:
Creating an instance using CREATE_OBJECT
Adressing a static attribute using
Calling a ststic attribute using CALL METHOD
Registering a static event handler
Registering an evetm handler method for a static event
The static constructor cannot be called explicitly.
Protected components
When we are talking subclassing and enheritance there is one more component than Public and Private, the Protected component. Protected components can be used by the superclass and all of the subclasses. Note that Subclasses cannot access Private components.
Polymorphism
Polymorphism: When the same method is implemented differently in different classes. This can be done using enheritance, by redefining a method from the superclass in subclasses and implement it differently.
Template for making a class
Delete the parts that should not be used
Definition part
CLASS xxx DEFINITION.
Public section
PUBLIC SECTION.
TYPES:
DATA:
Static data
CLASS-DATA:
Methods
METHODS:
Using the constructor to initialize parameters
constructor IMPORTING xxx type yyy,
Method with parameters
mm1 IMPORTING iii TYPE ttt.
Method without parameters
mm2.
Static methods
CLASS-METHODS:
Protected section. Also accessable by subclasses
PROTECTED SECTION.
Private section. Not accessable by subclasses
PRIVATE SECTION.
ENDCLASS.
Implementation part
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
ENDMETHOD.
METHOD mm1.
ENDMETHOD.
METHOD mm2.
ENDMETHOD.
ENDCLASS.
Template for calling a class
Create reference to class lcl_airplane
DATA: airplane1 TYPE REF TO lcl_airplane.
START-OF-SELECTION.
Create instance using parameters in the cosntructor method
CREATE OBJECT airplane1 exporting im_name = 'Hansemand'
im_planetype = 'Boing 747'.
Calling a method with parameters
CALL METHOD: airplane1->display_n_o_airplanes,
airplane1->display_attributes.
Subclass
CLASS xxx DEFINITION INHERITING FROM yyy.
Using af class as a parameter for a method
The class LCL_AIRPLANE is used as a parameter for method add_a_new_airplane:
METHODS:
add_a_new_airplane importing im_airplane TYPE REF to lcl_airplane.
Interfaces
In ABAP interfaces are implemented in addition to, and independently of classes. An interface only has a declaration part, and do not have visibillity sections. Components (Attributes, methods, constants, types) can be defined the same way as in classes.
Interfaces are listed in the definition part lof the class, and must always be in the PUBLIC SECTION.
Operations defined in the interface atre impemented as methods of the class. All methods of the interface must be present in the
implementation part of the class.
Attributes, events, constants and types defined in the interface are automatically available to the class carying out the implementation.
Interface components are adresse in the class by ]
Define, implement and use simple class
***INCLUDE ZBC404_HF_LCL_AIRPLANE .
Definition part
CLASS lcl_airplane DEFINITION.
Public section
PUBLIC SECTION.
TYPES: t_name(25) TYPE c.
METHODS:
constructor,
set_attributes IMPORTING p_name TYPE t_name
p_planetype TYPE saplane-planetype,
display_attributes,
display_n_o_airplanes.
Private section
PRIVATE SECTION.
Private attributes
DATA: name(25) TYPE c,
planetype TYPE saplane-planetype.
Private static attribute
CLASS-DATA n_o_airplanes TYPE i.
ENDCLASS.
Implementation part
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
Counts number of instances
n_o_airplanes = n_o_airplanes + 1.
ENDMETHOD.
METHOD set_attributes.
name = p_name.
planetype = p_planetype.
ENDMETHOD.
METHOD display_attributes.
WRITE:/ 'Name:', name, 'Planetype:', planetype.
ENDMETHOD.
METHOD display_n_o_airplanes.
WRITE: / 'No. planes:', n_o_airplanes.
ENDMETHOD.
ENDCLASS.
REPORT zbc404_hf_maintain_airplanes .
INCLUDE zbc404_hf_lcl_airplane.
Create reference to class lcl_airplane
DATA: airplane1 TYPE REF TO lcl_airplane,
airplane2 TYPE REF TO lcl_airplane.
START-OF-SELECTION.
Create instance
CREATE OBJECT airplane1.
CALL METHOD: airplane1->display_n_o_airplanes.
CREATE OBJECT airplane2.
Setting attributes using a method with parameters
CALL METHOD airplane1->set_attributes EXPORTING p_name = 'Kurt'
p_planetype = 'MD80'.
END-OF-SELECTION.
Using methods
CALL METHOD: airplane1->display_n_o_airplanes,
airplane1->display_attributes.
The resulting report:
Maintain airplanes
No. planes: 1
No. planes: 2
Name: Kurt Planetype: MD80
Use constructor to create an object with parameters
CLASS lcl_airplane DEFINITION.
PUBLIC SECTION.
TYPES: t_name(25) TYPE c.
METHODS:
constructor importing p2_name type t_name
p2_planetype TYPE saplane-planetype,
..... more code .......
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
name = p2_name.
planetype = p2_planetype.
..... more code .......
START-OF-SELECTION.
CREATE OBJECT airplane1 exporting p2_name = 'Hansemand'
p2_planetype = 'Boing 747'.
Subclassing
This example uses a superclass LCL_AIRPLANE and subclasses it into LCL_PASSENGER_AIRPLANE and LCL_CARGO_PLANE.
LCL_AIRPLANE has a method display_n_o_airplanes that displays the number of object instances.
LCL_PASSENGER_AIRPLANE has the private instance attribute n_o_seats, and redefines the superclass method display_attributes, so it also displays n_o_seats.
LCL_CARGO_PLANE has the private instance attribute cargomax, and redefines the superclass method display_attributes, so it also displays cargomax.
All instance attributes are provided by the cunstructor method.
Superclass LCL_AIRPLANE
***INCLUDE ZBC404_HF_LCL_AIRPLANE .
Definition part
CLASS lcl_airplane DEFINITION.
Public section
PUBLIC SECTION.
TYPES: t_name(25) TYPE c.
METHODS:
constructor IMPORTING im_name TYPE t_name
im_planetype TYPE saplane-planetype,
display_attributes.
Static methods
CLASS-METHODS:
display_n_o_airplanes.
Protected section
PROTECTED SECTION.
Private attributes
DATA: name(25) TYPE c,
planetype TYPE saplane-planetype.
Private static attribute
CLASS-DATA n_o_airplanes TYPE i.
ENDCLASS.
Implementation part
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
name = im_name.
planetype = im_planetype.
Counts number of instances
n_o_airplanes = n_o_airplanes + 1.
ENDMETHOD.
METHOD display_attributes.
WRITE:/ 'Name:', name, 'Planetype:', planetype.
ENDMETHOD.
METHOD display_n_o_airplanes.
WRITE: / 'No. planes:', n_o_airplanes.
ENDMETHOD.
ENDCLASS.
Sub class LCL_PASSENGER_AIRPLANE
***INCLUDE ZBC404_HF_LCL_PASSENGER_PLANE .
This is a subclass of class lcl_airplane
CLASS lcl_passenger_airplane DEFINITION INHERITING FROM lcl_airplane.
PUBLIC SECTION.
The constructor contains the parameters from the superclass
plus the parameters from the subclass
METHODS:
constructor IMPORTING im_name TYPE t_name
im_planetype TYPE saplane-planetype
im_n_o_seats TYPE sflight-seatsmax,
Redefinition of superclass method display_attributes
display_attributes REDEFINITION.
PRIVATE SECTION.
DATA: n_o_seats TYPE sflight-seatsmax.
ENDCLASS.
CLASS lcl_passenger_airplane IMPLEMENTATION.
METHOD constructor.
The constructor method of the superclass MUST be called withing the
construtor
CALL METHOD super->constructor
EXPORTING im_name = im_name
im_planetype = im_planetype.
n_o_seats = im_n_o_seats.
ENDMETHOD.
The redefined display_attributes method
METHOD display_attributes.
CALL METHOD super->display_attributes.
WRITE: / 'No. seats:', n_o_seats.
ENDMETHOD.
ENDCLASS.
Sub class LCL_CARGO_PLANE
***INCLUDE ZBC404_HF_LCL_CARGO_PLANE .
This is a subclass of class lcl_airplane
CLASS lcl_cargo_plane DEFINITION INHERITING FROM lcl_airplane.
PUBLIC SECTION.
METHODS:
The constructor contains the parameters from the superclass
plus the parameters from the subclass
constructor IMPORTING im_name TYPE t_name
im_planetype TYPE saplane-planetype
im_cargomax type scplane-cargomax,
Redefinition of superclass method display_attributes
display_attributes REDEFINITION.
PRIVATE SECTION.
DATA:cargomax TYPE scplane-cargomax.
ENDCLASS.
CLASS lcl_cargo_plane IMPLEMENTATION.
METHOD constructor.
The constructor method of the superclass MUST be called withing the
constructor
CALL METHOD super->constructor
EXPORTING im_name = im_name
im_planetype = im_planetype.
cargomax = im_cargomax.
ENDMETHOD.
METHOD display_attributes.
The redefined display_attributes method
CALL METHOD super->display_attributes.
WRITE: / 'Cargo max:', cargomax.
ENDMETHOD.
ENDCLASS.
The Main program that uses the classes
REPORT zbc404_hf_main .
Super class
INCLUDE zbc404_hf_lcl_airplane.
Sub classes
INCLUDE zbc404_hf_lcl_passenger_plane.
INCLUDE zbc404_hf_lcl_cargo_plane.
DATA:
Type ref to sub classes. Note: It is not necesssary to make typeref to the superclass
o_passenger_airplane TYPE REF TO lcl_passenger_airplane,
o_cargo_plane TYPE REF TO lcl_cargo_plane.
START-OF-SELECTION.
Display initial number of instances = 0
CALL METHOD lcl_airplane=>display_n_o_airplanes.
Create objects
CREATE OBJECT o_passenger_airplane
EXPORTING
im_name = 'LH505'
im_planetype = 'Boing 747'
im_n_o_seats = 350.
CREATE OBJECT o_cargo_plane
EXPORTING
im_name = 'AR13'
im_planetype = 'DC 3'
im_cargomax = 35.
Display attributes
CALL METHOD o_passenger_airplane->display_attributes.
CALL METHOD o_cargo_plane->display_attributes.
Call static method display_n_o_airplanes
Note: The syntax for calling a superclass method, differs from the syntax when calling a subclass method.
When calling a superclass => must be used instead of ->
CALL METHOD lcl_airplane=>display_n_o_airplanes.
Result:
No. planes: 0
Name: LH505 Planetype: Boing 747
No. seats: 350
Name: AR13 Planetype: DC 3
Cargo max: 35,0000
No. planes: 2
Polymorphism
Polymorphism: When the same method is implemented differently in different classes. This can be done using enheritance, by redefining a method from the superclass in subclasses and implement it differently.
Classes:
lcl_airplane Superclass
lcl_cargo_airplane Subclass
lcl_passenger_airplane Subclass
The method estimate_fuel_consumption is implemented differently in the 3 classes, as it depends on the airplane type.
Object from different classes are stored in an internal table (plane_list) consisting of references to the superclass, and the processed
identically for all the classes.
What coding for the estimate_fuel_consumption method taht is actually executed, depends on the dynamic type of the plane reference variable,
that is, depends on which object plane points to.
DATA: cargo_plane TYPE REF to lcl_cargo_airplane,
passenger_plane TYPE REF to lcl_passenger_airplane,
plane_list TYPE TABLE OF REF TO lcl_airplane.
Creating the list of references
CREATE OBJECT cargo_plane.
APPEND cargo_plane to plane_list.
CREATE OBJECT passenger_plane
APPEND passenger_plane to plane list.
Generic method for calucalting required fuel
METHOD calculate required_fuel.
DATA: plane TYPE REF TO lcl_airplane.
LOOP AT plane_list INTO plane.
re_fuel = re_fuel + plane->estimate_fuel_consumption( distance ).
ENDLOOP.
ENDMETHOD.
Working example:
This example assumes that the classes lcl_airplane, lcl_passnger_airplane and lcl_cargo plane (Se Subcallsing) exists.
Create objects of type lcl_cargo_plane and lcl_passenger_airplane, adds them to a list in lcl_carrier, and displays the list.
*& Include ZBC404_HF_LCL_CARRIER *
CLASS lcl_carrier DEFINITION *
CLASS lcl_carrier DEFINITION.
PUBLIC SECTION.
TYPES: BEGIN OF flight_list_type,
connid TYPE sflight-connid,
fldate TYPE sflight-fldate,
airplane TYPE REF TO lcl_airplane,
seatsocc TYPE sflight-seatsocc,
cargo(5) TYPE p DECIMALS 3,
END OF flight_list_type.
METHODS: constructor IMPORTING im_name TYPE string,
get_name RETURNING value(ex_name) TYPE string,
add_a_new_airplane IMPORTING
im_airplane TYPE REF TO lcl_airplane,
create_a_new_flight importing
im_connid type sflight-connid
im_fldate type sflight-fldate
im_airplane type ref to lcl_airplane
im_seatsocc type sflight-seatsocc
optional
im_cargo type p optional,
display_airplanes.
PRIVATE SECTION.
DATA: name TYPE string,
list_of_airplanes TYPE TABLE OF REF TO lcl_airplane,
list_of_flights TYPE TABLE OF flight_list_type.
ENDCLASS.
CLASS lcl_carrier IMPLEMENTATION
CLASS lcl_carrier IMPLEMENTATION.
METHOD constructor.
name = im_name.
ENDMETHOD.
METHOD get_name.
ex_name = name.
ENDMETHOD.
METHOD create_a_new_flight.
DATA: wa_list_of_flights TYPE flight_list_type.
wa_list_of_flights-connid = im_connid.
wa_list_of_flights-fldate = im_fldate.
wa_list_of_flights-airplane = im_airplane.
IF im_seatsocc IS INITIAL.
wa_list_of_flights-cargo = im_cargo.
ELSE.
wa_list_of_flights-seatsocc = im_seatsocc.
ENDIF.
APPEND wa_list_of_flights TO list_of_flights.
ENDMETHOD.
METHOD add_a_new_airplane.
APPEND im_airplane TO list_of_airplanes.
ENDMETHOD.
METHOD display_airplanes.
DATA: l_airplane TYPE REF TO lcl_airplane.
LOOP AT list_of_airplanes INTO l_airplane.
CALL METHOD l_airplane->display_attributes.
ENDLOOP.
ENDMETHOD.
ENDCLASS.
REPORT zbc404_hf_main .
This reprort uses class LCL_AIRPLNAE and subclasses
LCL_CARGO_PLANE and LCL_PASSENGER_AIRPLANE and class LCL_CARRIER
Super class for airplanes
INCLUDE zbc404_hf_lcl_airplane.
Sub classes for airplanes
INCLUDE zbc404_hf_lcl_passenger_plane.
INCLUDE zbc404_hf_lcl_cargo_plane.
Carrier class
INCLUDE zbc404_hf_lcl_carrier.
DATA:
Type ref to classes
o_passenger_airplane TYPE REF TO lcl_passenger_airplane,
o_passenger_airplane2 TYPE REF TO lcl_passenger_airplane,
o_cargo_plane TYPE REF TO lcl_cargo_plane,
o_cargo_plane2 TYPE REF TO lcl_cargo_plane,
o_carrier TYPE REF TO lcl_carrier.
START-OF-SELECTION.
Create objects
CREATE OBJECT o_passenger_airplane
EXPORTING
im_name = 'LH505'
im_planetype = 'Boing 747'
im_n_o_seats = 350.
CREATE OBJECT o_passenger_airplane2
EXPORTING
im_name = 'SK333'
im_planetype = 'MD80'
im_n_o_seats = 110.
CREATE OBJECT o_cargo_plane
EXPORTING
im_name = 'AR13'
im_planetype = 'DC 3'
im_cargomax = 35.
CREATE OBJECT o_cargo_plane2
EXPORTING
im_name = 'AFL124'
im_planetype = 'Iljutsin 2'
im_cargomax = 35000.
CREATE OBJECT o_carrier
EXPORTING im_name = 'Spritisch Airways'.
Add passenger and cargo planes to the list of airplanes
CALL METHOD o_carrier->add_a_new_airplane
EXPORTING im_airplane = o_passenger_airplane.
CALL METHOD o_carrier->add_a_new_airplane
EXPORTING im_airplane = o_passenger_airplane2.
CALL METHOD o_carrier->add_a_new_airplane
EXPORTING im_airplane = o_cargo_plane.
CALL METHOD o_carrier->add_a_new_airplane
EXPORTING im_airplane = o_cargo_plane2.
Display list of airplanes
call method o_carrier->display_airplanes.
Result:
Name: LH505 Planetype: Boing 747
No. seats: 350
Name: SK333 Planetype: MD80
No. seats: 110
Name: AR13 Planetype: DC 3
Cargo max: 35,0000
Name: AFL124 Planetype: Iljutsin 2
Cargo max: 35.000,0000
Events
Below is a simple example of how to implement an event.
REPORT zbc404_hf_events_5.
CLASS lcl_dog DEFINITION
CLASS lcl_dog DEFINITION.
PUBLIC SECTION.
Declare events
EVENTS:
dog_is_hungry
EXPORTING value(ex_time_since_last_meal) TYPE i.
METHODS:
constructor
IMPORTING im_name TYPE string,
set_time_since_last_meal
IMPORTING im_time TYPE i,
on_dog_is_hungry FOR EVENT dog_is_hungry OF lcl_dog
IMPORTING ex_time_since_last_meal.
ENDCLASS.
CLASS lcl_dog IMPLEMENTATION
CLASS lcl_dog IMPLEMENTATION.
METHOD constructor.
WRITE: / 'I am a dog and my name is', im_name.
ENDMETHOD.
METHOD set_time_since_last_meal.
IF im_time < 4.
SKIP 1.
WRITE: / 'You fool, I am not hungry yet'.
ELSE.
Subsrcribe for event:
set handler <Event handler method>
FOR <ref_sender>!FOR ALL INSTANCES [ACTIVATION <var>]
SET HANDLER on_dog_is_hungry FOR ALL INSTANCES ACTIVATION 'X'.
Raise event
RAISE EVENT dog_is_hungry
EXPORTING ex_time_since_last_meal = im_time.
ENDIF.
ENDMETHOD.
METHOD on_dog_is_hungry.
Event method, called when the event dog_is_hungry is raised
SKIP 1.
WRITE: / 'You son of a *****. I have not eaten for more than',
ex_time_since_last_meal, ' hours'.
WRITE: / 'Give me something to eat NOW!'.
ENDMETHOD.
ENDCLASS.
R E P O R T
DATA: o_dog1 TYPE REF TO lcl_dog.
START-OF-SELECTION.
CREATE OBJECT o_dog1 EXPORTING im_name = 'Beefeater'.
CALL METHOD o_dog1->set_time_since_last_meal
EXPORTING im_time = 2.
This method call will raise the event dog_is_hungy
because time > 3
CALL METHOD o_dog1->set_time_since_last_meal
EXPORTING im_time = 5.
Result:
I am a dog and my name is Beefeater
You fool, I am not hungry yet
You son of a *****. I have not eaten for more than 5 hours
Give me something to eat NOW!
1. Simple class
This example shows how to create a simple employee class. The constructor method is used to initialize number and name of thje employee when the object is created. A display_employee method can be called to show the attributes of the employee, and CLASS-METHOD dosplay_no_of_employees can be called to show the total number of employees (Number of instances of the employee class).
REPORT zbc404_hf_events_1.
L C L _ E M P L O Y E E
*---- LCL Employee - Definition
CLASS lcl_employee DEFINITION.
PUBLIC SECTION.
The public section is accesible from outside
TYPES:
BEGIN OF t_employee,
no TYPE i,
name TYPE string,
END OF t_employee.
METHODS:
constructor
IMPORTING im_employee_no TYPE i
im_employee_name TYPE string,
display_employee.
Class methods are global for all instances
CLASS-METHODS: display_no_of_employees.
PROTECTED SECTION.
The protecetd section is accesible from the class and its subclasses
Class data are global for all instances
CLASS-DATA: g_no_of_employees TYPE i.
PRIVATE SECTION.
The private section is only accesible from within the classs
DATA: g_employee TYPE t_employee.
ENDCLASS.
*--- LCL Employee - Implementation
CLASS lcl_employee IMPLEMENTATION.
METHOD constructor.
g_employee-no = im_employee_no.
g_employee-name = im_employee_name.
g_no_of_employees = g_no_of_employees + 1.
ENDMETHOD.
METHOD display_employee.
WRITE:/ 'Employee', g_employee-no, g_employee-name.
ENDMETHOD.
METHOD display_no_of_employees.
WRITE: / 'Number of employees is:', g_no_of_employees.
ENDMETHOD.
ENDCLASS.
R E P O R T
DATA: g_employee1 TYPE REF TO lcl_employee,
g_employee2 TYPE REF TO lcl_employee.
START-OF-SELECTION.
CREATE OBJECT g_employee1
EXPORTING im_employee_no = 1
im_employee_name = 'John Jones'.
CREATE OBJECT g_employee2
EXPORTING im_employee_no = 2
im_employee_name = 'Sally Summer'.
CALL METHOD g_employee1->display_employee.
CALL METHOD g_employee2->display_employee.
CALL METHOD g_employee2->display_no_of_employees.
2. Inheritance and polymorphism
This example uses a superclass lcl_company_employees and two subclasses lcl_bluecollar_employee and lcl_whitecollar_employee to add employees to a list and then display a list of employees and there wages. The wages are calcukated in the method add_employee, but as the wages are calculated differently for blue collar employees and white collar emplyees, the superclass method add_employee is redeifined in the subclasses.
Principles:
Create super class LCL_CompanyEmployees.
The class has the methods:
Constructor
Add_Employee - Adds a new employee to the list of employees
Display_Employee_List - Displays all employees and there wage
Display_no_of_employees - Displays total number of employees
Note the use of CLASS-DATA to keep the list of employees and number of employees the same from instance to instance.
Create subclasses lcl_bluecollar_employee and lcl_whitecollar_employee. The calsses are identical, except for the redifinition of the add_employee method, where the caclculation of wage is different.
Methodes:
Constructor. The constructor is used to initialize the attributes of the employee. Note that the constructor in the supclasss has to be called from within the constructor of the subclass.
Add_Employee. This is a redinition of the same method in the superclass. In the redefined class the wage is calcuated, and the superclass method is called to add the employees to the emploee list.:
The program
REPORT zbc404_hf_events_2 .
Super class LCL_CompanyEmployees
CLASS lcl_company_employees DEFINITION.
PUBLIC SECTION.
TYPES:
BEGIN OF t_employee,
no TYPE i,
name TYPE string,
wage TYPE i,
END OF t_employee.
METHODS:
constructor,
add_employee
IMPORTING im_no TYPE i
im_name TYPE string
im_wage TYPE i,
display_employee_list,
display_no_of_employees.
PRIVATE SECTION.
CLASS-DATA: i_employee_list TYPE TABLE OF t_employee,
no_of_employees TYPE i.
ENDCLASS.
*-- CLASS LCL_CompanyEmployees IMPLEMENTATION
CLASS lcl_company_employees IMPLEMENTATION.
METHOD constructor.
no_of_employees = no_of_employees + 1.
ENDMETHOD.
METHOD add_employee.
Adds a new employee to the list of employees
DATA: l_employee TYPE t_employee.
l_employee-no = im_no.
l_employee-name = im_name.
l_employee-wage = im_wage.
APPEND l_employee TO i_employee_list.
ENDMETHOD.
METHOD display_employee_list.
Displays all employees and there wage
DATA: l_employee TYPE t_employee.
WRITE: / 'List of Employees'.
LOOP AT i_employee_list INTO l_employee.
WRITE: / l_employee-no, l_employee-name, l_employee-wage.
ENDLOOP.
ENDMETHOD.
METHOD display_no_of_employees.
Displays total number of employees
SKIP 3.
WRITE: / 'Total number of employees:', no_of_employees.
ENDMETHOD.
ENDCLASS.
Sub class LCL_BlueCollar_Employee
CLASS lcl_bluecollar_employee DEFINITION
INHERITING FROM lcl_company_employees.
PUBLIC SECTION.
METHODS:
constructor
IMPORTING im_no TYPE i
im_name TYPE string
im_hours TYPE i
im_hourly_payment TYPE i,
add_employee REDEFINITION.
PRIVATE SECTION.
DATA:no TYPE i,
name TYPE string,
hours TYPE i,
hourly_payment TYPE i.
ENDCLASS.
*---- CLASS LCL_BlueCollar_Employee IMPLEMENTATION
CLASS lcl_bluecollar_employee IMPLEMENTATION.
METHOD constructor.
The superclass constructor method must be called from the subclass
constructor method
CALL METHOD super->constructor.
no = im_no.
name = im_name.
hours = im_hours.
hourly_payment = im_hourly_payment.
ENDMETHOD.
METHOD add_employee.
Calculate wage an call the superclass method add_employee to add
the employee to the employee list
DATA: l_wage TYPE i.
l_wage = hours * hourly_payment.
CALL METHOD super->add_employee
EXPORTING im_no = no
im_name = name
im_wage = l_wage.
ENDMETHOD.
ENDCLASS.
Sub class LCL_WhiteCollar_Employee
CLASS lcl_whitecollar_employee DEFINITION
INHERITING FROM lcl_company_employees.
PUBLIC SECTION.
METHODS:
constructor
IMPORTING im_no TYPE i
im_name TYPE string
im_monthly_salary TYPE i
im_monthly_deductions TYPE i,
add_employee REDEFINITION.
PRIVATE SECTION.
DATA:
no TYPE i,
name TYPE string,
monthly_salary TYPE i,
monthly_deductions TYPE i.
ENDCLASS.
*---- CLASS LCL_WhiteCollar_Employee IMPLEMENTATION
CLASS lcl_whitecollar_employee IMPLEMENTATION.
METHOD constructor.
The superclass constructor method must be called from the subclass
constructor method
CALL METHOD super->constructor.
no = im_no.
name = im_name.
monthly_salary = im_monthly_salary.
monthly_deductions = im_monthly_deductions.
ENDMETHOD.
METHOD add_employee.
Calculate wage an call the superclass method add_employee to add
the employee to the employee list
DATA: l_wage TYPE i.
l_wage = monthly_salary - monthly_deductions.
CALL METHOD super->add_employee
EXPORTING im_no = no
im_name = name
im_wage = l_wage.
ENDMETHOD.
ENDCLASS.
R E P O R T
DATA:
Object references
o_bluecollar_employee1 TYPE REF TO lcl_bluecollar_employee,
o_whitecollar_employee1 TYPE REF TO lcl_whitecollar_employee.
START-OF-SELECTION.
Create bluecollar employee obeject
CREATE OBJECT o_bluecollar_employee1
EXPORTING im_no = 1
im_name = 'Gylle Karen'
im_hours = 38
im_hourly_payment = 75.
Add bluecollar employee to employee list
CALL METHOD o_bluecollar_employee1->add_employee
EXPORTING im_no = 1
im_name = 'Gylle Karen'
im_wage = 0.
Create whitecollar employee obeject
CREATE OBJECT o_whitecollar_employee1
EXPORTING im_no = 2
im_name = 'John Dickens'
im_monthly_salary = 10000
im_monthly_deductions = 2500.
Add bluecollar employee to employee list
CALL METHOD o_whitecollar_employee1->add_employee
EXPORTING im_no = 1
im_name = 'Karen Johnson'
im_wage = 0.
Display employee list and number of employees. Note that the result
will be the same when called from o_whitecollar_employee1 or
o_bluecolarcollar_employee1, because the methods are defined
as static (CLASS-METHODS)
CALL METHOD o_whitecollar_employee1->display_employee_list.
CALL METHOD o_whitecollar_employee1->display_no_of_employees.
The resulting report
List of Employees
1 Karen Johnson 2.850
2 John Dickens 7.500
Total number of employees: 2
3. Interfaces
This example is similiar to th eprevious example, however an interface is implemented with the method add_employee. Note that the interface is only implemented in the superclass ( The INTERFACE stament), but also used in the subclasses.
The interface in the example only contains a method, but an iterface can also contain attrbutes, constants, types and alias names.
The output from example 3 is similiar to the output in example 2.
All changes in the program compared to example 2 are marked with red.
REPORT zbc404_hf_events_3 .
INTERFACE lif_employee
INTERFACE lif_employee.
METHODS:
add_employee
IMPORTING im_no TYPE i
im_name TYPE string
im_wage TYPE i.
ENDINTERFACE.
Super class LCL_CompanyEmployees
CLASS lcl_company_employees DEFINITION.
PUBLIC SECTION.
INTERFACES lif_employee.
TYPES:
BEGIN OF t_employee,
no TYPE i,
name TYPE string,
wage TYPE i,
END OF t_employee.
METHODS:
constructor,
add_employee "Removed
IMPORTING im_no TYPE i
im_name TYPE string
im_wage TYPE i,
display_employee_list,
display_no_of_employees.
PRIVATE SECTION.
CLASS-DATA: i_employee_list TYPE TABLE OF t_employee,
no_of_employees TYPE i.
ENDCLASS.
*-- CLASS LCL_CompanyEmployees IMPLEMENTATION
CLASS lcl_company_employees IMPLEMENTATION.
METHOD constructor.
no_of_employees = no_of_employees + 1.
ENDMETHOD.
METHOD lif_employee~add_employee.
Adds a new employee to the list of employees
DATA: l_employee TYPE t_employee.
l_employee-no = im_no.
l_employee-name = im_name.
l_employee-wage = im_wage.
APPEND l_employee TO i_employee_list.
ENDMETHOD.
METHOD display_employee_list.
Displays all employees and there wage
DATA: l_employee TYPE t_employee.
WRITE: / 'List of Employees'.
LOOP AT i_employee_list INTO l_employee.
WRITE: / l_employee-no, l_employee-name, l_employee-wage.
ENDLOOP.
ENDMETHOD.
METHOD display_no_of_employees.
Displays total number of employees
SKIP 3.
WRITE: / 'Total number of employees:', no_of_employees.
ENDMETHOD.
ENDCLASS.
Sub class LCL_BlueCollar_Employee
CLASS lcl_bluecollar_employee DEFINITION
INHERITING FROM lcl_company_employees.
PUBLIC SECTION.
METHODS:
constructor
IMPORTING im_no TYPE i
im_name TYPE string
im_hours TYPE i
im_hourly_payment TYPE i,
lif_employee~add_employee REDEFINITION..
PRIVATE SECTION.
DATA:no TYPE i,
name TYPE string,
hours TYPE i,
hourly_payment TYPE i.
ENDCLASS.
*---- CLASS LCL_BlueCollar_Employee IMPLEMENTATION
CLASS lcl_bluecollar_employee IMPLEMENTATION.
METHOD constructor.
The superclass constructor method must be called from the subclass
constructor method
CALL METHOD super->constructor.
no = im_no.
name = im_name.
hours = im_hours.
hourly_payment = im_hourly_payment.
ENDMETHOD.
METHOD lif_employee~add_employee.
Calculate wage an call the superclass method add_employee to add
the employee to the employee list
DATA: l_wage TYPE i.
l_wage = hours * hourly_payment.
CALL METHOD super->lif_employee~add_employee
EXPORTING im_no = no
im_name = name
im_wage = l_wage.
ENDMETHOD.
ENDCLASS.
Sub class LCL_WhiteCollar_Employee
CLASS lcl_whitecollar_employee DEFINITION
INHERITING FROM lcl_company_employees.
PUBLIC SECTION.
METHODS:
constructor
IMPORTING im_no TYPE i
im_name TYPE string
im_monthly_salary TYPE i
im_monthly_deductions TYPE i,
lif_employee~add_employee REDEFINITION.
PRIVATE SECTION.
DATA:
no TYPE i,
name TYPE string,
monthly_salary TYPE i,
monthly_deductions TYPE i.
ENDCLASS.
*---- CLASS LCL_WhiteCollar_Employee IMPLEMENTATION
CLASS lcl_whitecollar_employee IMPLEMENTATION.
METHOD constructor.
The superclass constructor method must be called from the subclass
constructor method
CALL METHOD super->constructor.
no = im_no.
name = im_name.
monthly_salary = im_monthly_salary.
monthly_deductions = im_monthly_deductions.
ENDMETHOD.
METHOD lif_employee~add_employee.
Calculate wage an call the superclass method add_employee to add
the employee to the employee list
DATA: l_wage TYPE i.
l_wage = monthly_salary - monthly_deductions.
CALL METHOD super->lif_employee~add_employee
EXPORTING im_no = no
im_name = name
im_wage = l_wage.
ENDMETHOD.
ENDCLASS.
R E P O R T
DATA:
Object references
o_bluecollar_employee1 TYPE REF TO lcl_bluecollar_employee,
o_whitecollar_employee1 TYPE REF TO lcl_whitecollar_employee.
START-OF-SELECTION.
Create bluecollar employee obeject
CREATE OBJECT o_bluecollar_employee1
EXPORTING im_no = 1
im_name = 'Gylle Karen'
im_hours = 38
im_hourly_payment = 75.
Add bluecollar employee to employee list
CALL METHOD o_bluecollar_employee1->lif_employee~add_employee
EXPORTING im_no = 1
im_name = 'Karen Johnson'
im_wage = 0.
Create whitecollar employee obeject
CREATE OBJECT o_whitecollar_employee1
EXPORTING im_no = 2
im_name = 'John Dickens'
im_monthly_salary = 10000
im_monthly_deductions = 2500.
Add bluecollar employee to employee list
CALL METHOD o_whitecollar_employee1->lif_employee~add_employee
EXPORTING im_no = 1
im_name = 'Gylle Karen'
im_wage = 0.
Display employee list and number of employees. Note that the result
will be the same when called from o_whitecollar_employee1 or
o_bluecolarcollar_employee1, because the methods are defined
as static (CLASS-METHODS)
CALL METHOD o_whitecollar_employee1->display_employee_list.
CALL METHOD o_whitecollar_employee1->display_no_of_employees.
4. Events
This is the same example as example 4. All changes are marked with red. There have been no canges to the subclasses, only to the superclass and the report, sp the code for th esubclasses is not shown.
For a simple example refer to Events in Examples.
REPORT zbc404_hf_events_4 .
INTERFACE lif_employee
INTERFACE lif_employee.
METHODS:
add_employee
IMPORTING im_no TYPE i
im_name TYPE string
im_wage TYPE i.
ENDINTERFACE.
Super class LCL_CompanyEmployees
CLASS lcl_company_employees DEFINITION.
PUBLIC SECTION.
TYPES:
BEGIN OF t_employee,
no TYPE i,
name TYPE string,
wage TYPE i,
END OF t_employee.
Declare event. Note that declaration could also be placed in the
interface -
Hi experts.,
i am very new in abap oo . please give me documentation and if possible sample code.
thanks in advance,Some documentation related with OOPs Abao :
oops_beginers
http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
ALV Gird Control (BC-SRV-ALE)
SAP Container
SAP Control Framework
or Thread New To OOPs ABAP
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sap.km.cm.docs/library/webas/abap/abap%20code%20samples/abap%20objects/abap%20code%20sample%20to%20learn%20basic%20concept%20of%20object-oriented%20programming.doc
General Tutorial for OOPS
check all the below links
http://www.sapgenie.com/abap/OO/index.htm
http://www.geocities.com/victorav15/sapr3/abap_ood.html
http://www.brabandt.de/html/abap_oo.html
Check this cool weblog:
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b6254f411d194a60000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://www.esnips.com/doc/375fff1b-5a62-444d-8ec1-55508c308b17/prefinalppt.ppt
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://www.allsaplinks.com/
http://www.sap-img.com/
http://www.sapgenie.com/
http://help.sap.com
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://www.sapgenie.com/abap/controls/index.htm
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
these links
http://help.sap.com/saphelp_47x200/helpdata/en/ce/b518b6513611d194a50000e8353423/content.htm
For funtion module to class
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5954f411d194a60000e8353423/content.htm
for classes
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5c54f411d194a60000e8353423/content.htm
for methods
http://help.sap.com/saphelp_47x200/helpdata/en/08/d27c03b81011d194f60000e8353423/content.htm
for inheritance
http://help.sap.com/saphelp_47x200/helpdata/en/dd/4049c40f4611d3b9380000e8353423/content.htm
for interfaces
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b6254f411d194a60000e8353423/content.htm
Check these links.
http://www.henrikfrank.dk/abapuk.html
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sap.km.cm.docs/library/webas/abap/abap%20code%20samples/abap%20objects/abap%20code%20sample%20to%20learn%20basic%20concept%20of%20object-oriented%20programming.doc
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sap.km.cm.docs/library/webas/abap/abap%20code%20samples/alv%20grid/abap%20code%20sample%20to%20display%20data%20in%20alv%20grid%20using%20object%20oriented%20programming.doc
Go through the below links,
For Materials:
1) http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCABA/BCABA.pdf -- Page no: 1291
2) http://esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
3) http://esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
4) http://esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
5) http://esnips.com/doc/92be4457-1b6e-4061-92e5-8e4b3a6e3239/Object-Oriented-ABAP.ppt
6) http://esnips.com/doc/448e8302-68b1-4046-9fef-8fa8808caee0/abap-objects-by-helen.pdf
7) http://esnips.com/doc/39fdc647-1aed-4b40-a476-4d3042b6ec28/class_builder.ppt
8) http://www.amazon.com/gp/explorer/0201750805/2/ref=pd_lpo_ase/102-9378020-8749710?ie=UTF8
OO ABAP links:
1) http://www.erpgenie.com/sap/abap/OO/index.htm
2) http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
go through these links
http://www.erpgenie.com/abap/index.htm
http://sic.fh-lu.de/sic/bic.nsf/(vJobangebote)/EC8AD2AE0349CE92C12572200026FDB8/$File/Intern%20or%20Working%20Student%20as%20ABAB%20OO%20Developer.pdf?Open
http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm
http://help.sap.com/saphelp_47x200/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
ABAP_OBJECTS_ENJOY_0 Template for Solutions of ABAP Object Enjoy Course
ABAP_OBJECTS_ENJOY_1 Model Solution 1: ABAP Objects Enjoy Course
ABAP_OBJECTS_ENJOY_2 Model Solution 2: ABAP Objects Enjoy Course
ABAP_OBJECTS_ENJOY_3 Model Solution 3: ABAP Objects Enjoy Course
ABAP_OBJECTS_ENJOY_4 Model Solution 4: ABAP Objects Enjoy Course
ABAP_OBJECTS_ENJOY_5 Model Solution 5: ABAP Objects Enjoy Course
DEMO_ABAP_OBJECTS Complete Demonstration for ABAP Objects
DEMO_ABAP_OBJECTS_CONTROLS GUI Controls on Screen
DEMO_ABAP_OBJECTS_EVENTS Demonstration of Events in ABAP Objects
DEMO_ABAP_OBJECTS_GENERAL ABAP Objects Demonstration
DEMO_ABAP_OBJECTS_INTERFACES Demonstration of Interfaces in ABAP Objects
DEMO_ABAP_OBJECTS_METHODS Demonstration of Methods in ABAP Objects
DEMO_ABAP_OBJECTS_SPLIT_SCREEN Splitter Control on Screen
check the below links lot of info and examples r there
http://www.sapgenie.com/abap/OO/index.htm
http://www.geocities.com/victorav15/sapr3/abap_ood.html
http://www.brabandt.de/html/abap_oo.html
Check this cool weblog:
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b6254f411d194a60000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://www.esnips.com/doc/375fff1b-5a62-444d-8ec1-55508c308b17/prefinalppt.ppt
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://www.allsaplinks.com/
http://www.sap-img.com/
http://www.sapgenie.com/
http://help.sap.com
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://www.sapgenie.com/abap/controls/index.htm
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
these links
http://help.sap.com/saphelp_47x200/helpdata/en/ce/b518b6513611d194a50000e8353423/content.htm
For funtion module to class
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5954f411d194a60000e8353423/content.htm
for classes
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5c54f411d194a60000e8353423/content.htm
for methods
http://help.sap.com/saphelp_47x200/helpdata/en/08/d27c03b81011d194f60000e8353423/content.htm
for inheritance
http://help.sap.com/saphelp_47x200/helpdata/en/dd/4049c40f4611d3b9380000e8353423/content.htm
for interfaces
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b6254f411d194a60000e8353423/content.htm
For Materials:
1) http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCABA/BCABA.pdf -- Page no: 1291
2) http://esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
3) http://esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
4) http://esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
5) http://esnips.com/doc/92be4457-1b6e-4061-92e5-8e4b3a6e3239/Object-Oriented-ABAP.ppt
6) http://esnips.com/doc/448e8302-68b1-4046-9fef-8fa8808caee0/abap-objects-by-helen.pdf
7) http://esnips.com/doc/39fdc647-1aed-4b40-a476-4d3042b6ec28/class_builder.ppt
8) http://www.amazon.com/gp/explorer/0201750805/2/ref=pd_lpo_ase/102-9378020-8749710?ie=UTF8
1) http://www.erpgenie.com/sap/abap/OO/index.htm
2) http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
ALVOOPS
http://www.abap4.it/download/ALV.pdf
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/e8a1d690-0201-0010-b7ad-d9719a415907
http://www.erpgenie.com/abap/controls/alvgrid.htm
OOPS with ABAP
https://www.sdn.sap.com/irj/sdn/wiki?path=/pages/viewpage.action&pageid=37566
/people/rich.heilman2/blog/2005/07/27/dynamic-internal-tables-and-structures--abap
http://www.sapgenie.com/abap/OO/
For understanding COntrol Frameworks in OO ABAP, check this.
http://www.sapgenie.com/abap/controls/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/content.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://www.esnips.com/doc/375fff1b-5a62-444d-8ec1-55508c308b17/prefinalppt.ppt
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://www.allsaplinks.com/
http://www.sap-img.com/
http://www.sapgenie.com/
http://help.sap.com
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com.
http://www.sapgenie.com/abap/OO/index.htm
http://www.sapgenie.com/abap/controls/index.htm
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://www.geocities.com/victorav15/sapr3/abap_ood.html
http://www.brabandt.de/html/abap_oo.html
ALVOOPS
http://www.erpgenie.com/abap/controls/alvgrid.htm
OOPS with ABAP
https://www.sdn.sap.com/irj/sdn/wiki?path=/pages/viewpage.action&pageid=37566
/people/rich.heilman2/blog/2005/07/27/dynamic-internal-tables-and-structures--abap
http://www.sapgenie.com/abap/OO/
For understanding COntrol Frameworks in OO ABAP, check this.
http://www.sapgenie.com/abap/controls/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/content.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://www.esnips.com/doc/375fff1b-5a62-444d-8ec1-55508c308b17/prefinalppt.ppt
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://www.allsaplinks.com/
http://www.sap-img.com/
http://www.sapgenie.com/
http://help.sap.com
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com.
http://www.sapgenie.com/abap/OO/index.htm
http://www.sapgenie.com/abap/controls/index.htm
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://www.geocities.com/victorav15/sapr3/abap_ood.html
http://www.brabandt.de/html/abap_oo.html
Regarding ALV Grid Control using OOPs concepts
Regarding ALV Grid Control using OOPs concepts
OOPS OO ABAP
http://esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://esnips.com/doc/92be4457-1b6e-4061-92e5-8e4b3a6e3239/Object-Oriented-ABAP.ppt
http://esnips.com/doc/448e8302-68b1-4046-9fef-8fa8808caee0/abap-objects-by-helen.pdf
http://esnips.com/doc/39fdc647-1aed-4b40-a476-4d3042b6ec28/class_builder.ppt
http://www.amazon.com/gp/explorer/0201750805/2/ref=pd_lpo_ase/102-9378020-8749710?ie=UTF8
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
DIRLL DOWN AND INTERACTIVE REPORT
http://www.sap-img.com/abap/difference-between-drilldown-report-and-interactive-report.htm
PAGE BREAK FOR ALV LIST
check out this link
http://www.abap4.it/download/ALV.pdf
good book on ABAP objects(OOPS)
http://www.esnips.com/doc/bc475662-82d6-4412-9083-28a7e7f1ce09/Abap-Objects---An-Introduction-To-Programming-Sap-Applications
How to check Cluster Table Data
https://forums.sdn.sap.com/click.jspa?searchID=5215473&messageID=3520315
http://www.sap-img.com/abap/the-different-types-of-sap-tables.htm
http://help.sap.com/saphelp_47x200/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm
Check this cool weblog:
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
/people/thomas.jung3/blog/2004/12/08/abap-persistent-classes-coding-without-sql
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b6254f411d194a60000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_nw04/helpdata/en/c3/225b5654f411d194a60000e8353423/content.htm
http://www.esnips.com/doc/375fff1b-5a62-444d-8ec1-55508c308b17/prefinalppt.ppt
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
http://www.allsaplinks.com/
http://www.sap-img.com/
http://www.sapgenie.com/
http://help.sap.com
http://www.sapgenie.com/abap/OO/
http://www.sapgenie.com/abap/OO/index.htm
http://www.sapgenie.com/abap/controls/index.htm
http://www.esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
http://www.esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
http://www.sapgenie.com/abap/OO/index.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
http://www.sapgenie.com/abap/OO/
these links
http://help.sap.com/saphelp_47x200/helpdata/en/ce/b518b6513611d194a50000e8353423/content.htm
For funtion module to class
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5954f411d194a60000e8353423/content.htm
for classes
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b5c54f411d194a60000e8353423/content.htm
for methods
http://help.sap.com/saphelp_47x200/helpdata/en/08/d27c03b81011d194f60000e8353423/content.htm
for inheritance
http://help.sap.com/saphelp_47x200/helpdata/en/dd/4049c40f4611d3b9380000e8353423/content.htm
for interfaces
http://help.sap.com/saphelp_47x200/helpdata/en/c3/225b6254f411d194a60000e8353423/content.htm
For Materials:
1) http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCABA/BCABA.pdf -- Page no: 1291
2) http://esnips.com/doc/5c65b0dd-eddf-4512-8e32-ecd26735f0f2/prefinalppt.ppt
3) http://esnips.com/doc/2c76dc57-e74a-4539-a20e-29383317e804/OO-abap.pdf
4) http://esnips.com/doc/0ef39d4b-586a-4637-abbb-e4f69d2d9307/SAP-CONTROLS-WORKSHOP.pdf
5) http://esnips.com/doc/92be4457-1b6e-4061-92e5-8e4b3a6e3239/Object-Oriented-ABAP.ppt
6) http://esnips.com/doc/448e8302-68b1-4046-9fef-8fa8808caee0/abap-objects-by-helen.pdf
7) http://esnips.com/doc/39fdc647-1aed-4b40-a476-4d3042b6ec28/class_builder.ppt
8) http://www.amazon.com/gp/explorer/0201750805/2/ref=pd_lpo_ase/102-9378020-8749710?ie=UTF8
1) http://www.erpgenie.com/sap/abap/OO/index.htm
2) http://help.sap.com/saphelp_nw04/helpdata/en/ce/b518b6513611d194a50000e8353423/frameset.htm
COLOURING Single Columan
http://www.sapfans.com/forums/viewtopic.php?t=52107
Check this thread to get more idea about ALVs.
Interactive ALV
Rewards if useful.............
Minal -
Is oracle OODBMS (Object Oriented database management system)?
Hello, All
Is oracle OODBMS (Object Oriented database management system)? and if yes, please explain.
I have query in my mind so, I just posted here.
Regards,
Rahul
Edited by: Rahul K. Thakar on Nov 3, 2010 12:03 PM
Edited by: Rahul K. Thakar on Nov 3, 2010 12:04 PMI believe the precise answer is that Oracle is ORDBMS (Object-Relational DBMS).For a brief period in time Oracle Corporation offered a product called Object Oriented Oracle (OOO).
It was such a wonderous product that it was buried in the trash can of history when it did neither task very well. -
Only oracle object tables to create object oriented database
Can we use only oracle object tables for a database and if it can be done, can we create pure object oriented database with oracle. How it can be done?
help..
thank you..PriyashanthaHP wrote:
I have no my own definitions for OODB. There are lot in the internet. I'm asking, can't we use that OODB concept with oracle. And gave you an example with 'employee' and 'department' tables. I asked that can we create object tables for these two tables keeping their relationship
thank you..
There is no way to answer that without knowing what YOU mean by OODB.
See the database concepts doc
http://docs.oracle.com/cd/B28359_01/server.111/b28318/schema.htm
Nested Tables
You can create a table with a column whose datatype is another table. That is, tables can be nested within other tables as values in a column. The Oracle database server stores nested table data out of line from the rows of the parent table, using a store table that is associated with the nested table column. The parent row contains a unique set identifier value associated with a nested table instance.
Oracle Database Object-Relational Developer's Guidefor further information on nested tables
Oracle Database Advanced Application Developer's Guide -
Can I develop a 100% Object Oriented DB with Oracle 10g?
Hello!
I need to know if I can develop a pure Object Oriented Data Base? because I have been looking for this information, and I just found Oracle's arquitecture is oriented to relational object model.
Thanks!
Edited by: 925803 on 05-abr-2012 10:39Dear "925803",
1) You're asking this question in the Oracle Application Express discussion forum - not really related to generic Database questions. This Database forum may be more suited: General Database Discussions
2) The Oracle database is not an object-oriented database.
Joel -
Perhaps the way I raised this question would be peculiar for you as I'm a newbie!
I'm willing to use oracle object oriented programing for my applications, and some senior people(work in my organization) told me that Object oriented database concept is failed in the industry. As a reason they say that; even if Object oriented databases solved some problems people had with relational databases, still Object oriented databases are failed to facilitate most of the advantages of relational databases. It's somewhat chaotic for me, as I'm new to PL developments.
They didn't mention any specific reason; but just told me that relational databases perform well and faster than object oriented databases, and for business logic, object oriented databases has some accuracy issues.
But I'm not ready to accept that it will be useless to learn 'Oracle Object Oriented Programing' or 'Object Oriented Database Concept' would be failed.
So I need to know,
1. Will it be useless to learn & use 'OOP' techniques when learning PL/SQL programing?
2. Is there any disadvantage of using 'OOP' with oracle? (If there is any, please let me know if you have time for that).
Especially, (The most pleasing answer I would like to hear from you ;-) )
3. If Object Oriented Databases concept is better and something that a "PL/SQL" developer must learn; please let me know that.
Please provide me a link if you can, which would help me to learn why should we use 'OOP' with oracle (if Object oriented database is better than Relational database)Intruder wrote:
So I need to know,
1. Will it be useless to learn & use 'OOP' techniques when learning PL/SQL programing?No. OOP has very little do with relational database design. The two is not mutually exclusive and can co-exist easily.
2. Is there any disadvantage of using 'OOP' with oracle? (If there is any, please let me know if you have time for that).That depends on how+ you use it. If OOP was truly horrible and bad, then why does Oracle spend money on the research and development on it for their RDBMS product?
Especially, (The most pleasing answer I would like to hear from you ;-) )
3. If Object Oriented Databases concept is better and something that a "PL/SQL" developer must learn; please let me know that.OOP is not Object Orientated Database. These are two very different concepts. OOP competes with procedural programming. Object Orientated Database design competes with Relational Database Design (and others of course).
There are two primary issues with an Object Orientated Database design. Complexity. Performance.
Do you for example store the subclasses of the same abstract class in the same physical object table? You can do that in Oracle.. but then the database need to resolve the class type at run-time.. every single time.. for every single object accessed... At what cost ito performance?
How do you treat collection classes? A collection can be stored as a physical table. It can also be stored as an attribute (column) of an object (table) - in which case the physical implementation for that is a nested table. There are dire performance issues with nested tables when these are used and applied incorrectly.
There are numerous such issues.
Compare this with something as mature and robust as Relational Database Design. Easy to understand. Easy to use. And what the Oracle RDBMS product was specifically designed to support.
Which one is "+better+" (especially in the Oracle RDBMS environment)? It should be obvious.
I suggest that you read Codd's original paper on "+A Relation Model of Data for Large Shared Data Banks+", read "+The Third Manifesto+" from Chris Date, and papers from various other authors for insight. -
Join Query in Object Oriented Programming
Hi,
I am trying to understand better how OO programming should work in CFC context. For example, I have two database tables: Customer and Order. So I create two CFCs, one for Customer and another for Order. In the CFCs I have query functions (select, insert, update) to access and manipulate data in the underlying tables.
Now, I need to create a new CFC, OrderReport. This CFC takes in customerID and returns data pulled from both Customer and Order tables. I can just have a join query that pulls data from these two tables. However, I have been wondering whether this method is within the spirit of Object Oriented programming. Should this CFC be able to access directly to the two tables? Or should I pull data separately using Customer CFC and Order CFC, and join them locally (ie. in OrderReport CFC)? This latter method would be a lot slower to run than the first method.
Can you advise me as to what the best practice is in the context of OO programming? Thank you.This is a common question for those new to OO programming. Here are some of
my thoughts on the topic.
OO programming has nothing to do with tables. Your tables are essentially a
relational storage of one part of a business concept. It just so happens
that most of the data you need to support the business concept of Customer
and the business concept of Order are stored in tables named Customer and
Order. This is because database tables often relate to a business concept. I
think you'd find that to get the entire customer, you'd have to get data
from other tables, like State and Gender and other such tables.
The reason why I bring this up is to begin to separate your thinking.
Databases are concerned with efficient storage and retrieval of data.
Objects (CFCs) are not concerned at all with storage of data. Objects are
concerned with encapsulating business logic relating to a business concept.
Just like your database may have columns not needed by your CFCs, your CFCs
likely have methods not needed by your database.
For example, if you wanted to know, in your application, whether to show an
In Store Pickup option, you may wish to add an isLocal() method to your
customer object. This would ( we'll pretend) get the customer's zip code,
and look it up in GeographicalPostalServiceMapper object to tell us how far
away the customer is.
The point is, the right OO (CFC) design has nothing to do with how your
tables are organized in the database. You would do well to concern yourself
with the needs of the application and what sort of questions you need your
customer object to be able to answer to the other parts of your application.
Like, isLocal(), isOver21(), isBadCreditRisk() and so on.
As to your question about joins, you would do well to use joins in your
application. Do not be afraid of using queries to get the information you
need. Especially for reporting queries. In these cases, I often make an
object called a xxxList. My CustomerList.cfc would have the different ways
to list customer data, like CustomerOrders and CustomerOrderReturns. I'd
hide this join relationship inside of the CustomerList object so only the
CustomerList object has the SQL. That's usually enough encapsulation for the
needs of my application.
Truly, it doesn't matter what the name of the object is, just that you
assign it the responsibility of managing a business concept and keep that
business concept inside that object. You seem to have suggested
CustomerReport.cfc and that would be a fine name for an object that can
return numerous Customer Reports.
Happy Coding
DW -
ANN: PHP Object-Oriented Solutions
This is not directly related to Dreamweaver, but I know a lot
of people
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Ken Ford
Adobe Community Expert Dreamweaver/ColdFusion
Fordwebs, LLC
http://www.fordwebs.com
"Joe Makowiec" <[email protected]> wrote in
message
news:[email protected]..
> On 19 Aug 2008 in macromedia.dreamweaver.appdev, David
Powers wrote:
>
>> Michael White wrote:
>>> From where do you recommend I buy it? (NY, USA)
>>
>> The place that would bring the greatest benefit to
me is through the
>> Amazon.com link on my site (see link in my sig).
Amazon in the USA
>> is offering it at a 34% discount. However, I'm
delighted if anyone
>> buys it anywhere.
>
> I didn't see a link to US Amazon, only Canada and UK?
>
> --
> Joe Makowiec
>
http://makowiec.net/
> Email:
http://makowiec.net/contact.php
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