Use of primary key

hi guru
without using primary key, is this possible to create table.
regards
subhasis.

hi,
I will explain with simple example.
suppose there is table storing passport number and name of employye.
so the developer created a table with these two fields, and there is no primary key in that.
so when inserting data, any 1 can insert any data with duplicates value.. just imagina situation where two people has same passport number, due to this bad data base design.
so the solution is to avoid duplicate entries, for that we haev to cmake passport number as primary key.it will vaoid duplicate entries.
hipe u undrstud.
Rgds
Anversha

Similar Messages

Use multiple primary keys to create DB constraint

Hi,
Is it possible to have multiple primary keys within one EJB to create a DB including the constraints, if so how? Is there an example of this or any example which uses multiple primary keys to create a DB?
Thanks,
Maarten

"Is it possible to have multiple primary keys within one EJB..."
If you mean a composite key, yes. Your PrimaryKeyObject would have one attribute for each column that makes up your composite key. If that's not what you meant, please clarify.
"...to create a DB including the constraints"
Not sure what you mean here. Constraints are enforced by the DB, and you don't create databases with EntityBeans.

Having a problem with creating/using a primary key on a view

I have a problem with a primary key on a view
I created the view and primary key as follows:
CREATE OR REPLACE FORCE VIEW "MDD"."ROCK_LU" ("DESCRIPTION",
UNIQUE ("DESCRIPTION") RELY DISABLE,
CONSTRAINT "ROCK_LU_PK" PRIMARY KEY ("DESCRIPTION") RELY DISABLE) AS
SELECT DESCRIPTION
FROM MRMC_LU
WHERE ROCK = 'T';
The view with the primary key appears to have been created as there were no error messages. (The above was from the sql tab in sql developer.)
When I try to create the foreign key on my mdd_hr table - I get an error
/* hr_name - foreign key */
ALTER TABLE mdd_hr add CONSTRAINT hr_name_fk FOREIGN KEY (hr_name) REFERENCES rock_lu(description);
Error report:
SQL Error: ORA-02270: no matching unique or primary key for this column-list.
When I lookup the index in sql developer, rock_lu_pk is not there.
All my other foreign keys work - but I don't understand what I am doing wrong with this one. Please help.
glenn
Background - as to why I want to use a view as a lookup table.
The MRMC_LU table that the view is created from is structured like:
DESCRIPTION - MINERAL - ROCK - MODIFIER - COMMODITY
ANHYDRITE - T - T - T
APLITE - T - - T
GRAPHITE - T - - - T
GREYWACKE - - T
DESCRIPTION is a list of all names of minerals, rocks, modifiers and commodities. T is entered in each valid field. Often a description name is used for both a mineral and a rock or a mineral and a commodity or any other combination. Because this database is just starting up, it was more efficient to create one table that could be updated (and thereby automatically update the MINERAL_LU, ROCK_LU, MODIFIER_LY, COMMODITY_LU views) rather than create and maintain four separate but similar tables. A primary key cannot be generated for the MRMC_LU table as there are nulls in each column
except DESCRIPTION.
Perhaps there is a smarter way to do this?

http://download-uk.oracle.com/docs/cd/B10501_01/server.920/a96540/statements_85a.htm#2065512
You can specify constraints on views and object views. You define the constraint at the view level using the out_of_line_constraint clause. You define the constraint as part of column or attribute specification using the inline_constraint clause after the appropriate alias.
Oracle does not enforce view constraints. However, operations on views are subject to the integrity constraints defined on the underlying base tables. This means that you can enforce constraints on views through constraints on base tables.
Restrictions on View Constraints
View constraints are a subset of table constraints and are subject to the following restrictions:
You can specify only unique, primary key, and foreign key constraints on views. However, you can define the view using the WITH CHECK OPTION clause, which is equivalent to specifying a check constraint for the view.
Because view constraints are not enforced directly, you cannot specify INITIALLY DEFERRED or DEFERRABLE.
View constraints are supported only in DISABLE NOVALIDATE mode. You must specify the keywords DISABLE NOVALIDATE when you declare the view constraint, and you cannot specify any other mode.
You cannot specify the using_index_clause, the exceptions_clause clause, or the ON DELETE clause of the references_clause.
You cannot define view constraints on attributes of an object column.
Rgds.

Error with Links if using x3 primary keys

Hi Folks:
Here is the error code I'm receiving:
ORA-01422: exact fetch returns more than requested number of rows
Unable to fetch row.
Background: I am using Application Express 3.2
All of the pages I have created that rely on x2 primary keys (first_name, last_name) work fine.
I have a table that has x3 primary keys: Table is called "time_off_awards". The x3 primary keys are: last_name, first_name, approval_date.
I created a report that works properly and lists the awards for each person (each person can receive more than one award-on different dates).
I also created an edit link that works properly IF *(only if)* each individual has only one award. If the individual has more than one award then I get the error above. When I set up the link I used all three keys. The x3 PK's should uniquely identify each row, but if the same last name/first name appear more than once (that is if the person has more than one award) I get the error. I thought at first maybe it was just not reading the 3rd key/part of the link (approval_date), but it shows properly if you move your cursor over the edit link.
Here is a link to a screen pic of how I have my link set in Apex:
[http://www.wczone.com/link_settings.gif]
Here is a link to a pic of the report with some info:
[http://www.wczone.com/report_link.gif]
If needed, here is my table info:
CREATE TABLE PERSONNEL.TIME_OFF_AWARDS (
LAST_NAME VARCHAR2(40) NOT NULL,
FIRST_NAME VARCHAR2(25) NOT NULL,
APPROVAL_DATE DATE NOT NULL,
HOURS_OFF NUMBER(3),
CITATION VARCHAR2(1500),
/* Keys */
PRIMARY KEY (LAST_NAME, FIRST_NAME, APPROVAL_DATE),
/* Foreign keys */
CONSTRAINT TOA_PERSONNEL
FOREIGN KEY (LAST_NAME, FIRST_NAME)
REFERENCES PERSONNEL.MARC_PERSONNEL(LAST_NAME, FIRST_NAME)
TABLESPACE PERSONNEL;
Thanks for any help, I've tried looking at a couple of Apex books, but they didn't help much.
Matt
Edited by: user10495310 on Mar 4, 2009 8:21 AM

Thank you everyone for the help and information you gave to me.
Your ideas and advice helped me to think through the issues involved.
The way i actually found to work around this issue was a little different.
What I did was the following (which may only be usable with empty tables. If its possible to create a new column with a sequence and trigger on a table that already contains data it should work also):
1. I removed the current PK's that were currently set.
2. I added a single, unique PK (that used a sequence and trigger to automatically increment) to the table as was suggested in this thread and other APEX forum threads.
3. I changed the link on the report so that it used the new PK, and also changed the PK used on the forms (under Processes - both the page rendering and page processing processes).
The Difference:
4. Next I changed the table (not by using APEX, but directly) from using the automatically generated ID as the PK, back to using the compound PK (x3 keys). I then added an constraint to make sure that the automatically generated column was unique. So now I have the compound PK that my supervisor wants us to use, and I'm able to use a unique, automatically generated key for APEX to use.
I found also that if you already have a column that uses a unique/auto-generated key you can still use it with APEX without switching keys around.
1. I added the new column to the sql in the reports source section so that the new column was searched (and then used 'hidden' so it wouldn't be displayed on the report users would see).
2. You can still add the unique key under the processes on the form that is being linked too under the Primary key tabs. If its not a PK it won't show up in the pop up which is to the right of "Item Containing Primary Key Column Value" but it can be entered manually (i.e. p23_AUTO_ID) and it will work fine. You would also need to edit your form so that the auto ID that is being passed from the report is part of the form - but hidden if desired).

I am trying to create a sequence to be use as primary key in a Oracle table

Hi guys
I have the ODI version 10.3.5 and I am trying to create a sequence that populates de row_id for a table. The schema is a database.
And I want that this item will be the primary key of the table that is loaded at execute the interface however I'm getting issues.
So please advise me.

Hi ,
Can you please provide the following details :
1. What is the execution area of your sequence ? Is it source or staging or Target.
2. What IKM you are using ( I hope you are executing sequence in Staging or Target ) ?
My understanding is when you check Not Null , all your rows are going to Error table. So it is not giving any error.
When you uncheck the Not Null , it is giving error because Database is not allowing Null values in the Primary Key Column.
You can do the following to check if your sequence is working properly.
Try to write a Insert Select query in DB and execute it and see if it is working properly.
i.e.
insert into      EMPL     (
     EMPNO,
     ENAME,
     JOB,
     MGR,
     HIREDATE,
     SAL,
     COMM,
     DEPTNO
select      S_EMPNO.NEXTVAL,
     ENAME,
     JOB,
     MGR,
     HIREDATE,
     SAL,
     COMM,
     DEPTNO
from     EMP
or if you can provide your query in this format , it will help in finding the issue quickly.Also provide the KM details.

How to use 2 primary key in 1 table

Hi,
When i creating the table,in this the following are the columns Name,Street,City,Pin in this they give some rules the column Name & City as Primary Key. But when type the query it shows the error table contains one primary key, how i do this? Tell the mistakes

Hi,
Welcome to the forum!
Whenever you have a question, please post your code. Ithelps people understand what the problem is. and allows them to test ideas.
1000492 wrote:
Hi,
When i creating the table,in this the following are the columns Name,Street,City,Pin in this they give some rules the column Name & City as Primary Key. But when type the query What do you mean by "But when type the query"?
Do you mean "But when I run this query ..."?
it shows the error table contains one primary key, how i do this? What is the query you're running? What are the results? Did you expect other results? What results did you expect? Why?
Tell the mistakesThere are not necessarily any mistakes.
By definition, a table can never have more than 1 primary key. (If needed, a table can have any number of unique keys, that are like primary keys in everything but name.)
Any key, primary or unique, can be composed of 1, 2, 3 or more columns.

Use of end-date as part of Primary key in SAP Tables

All,
Any ideas on the rationale behind SAPs use of end-date as part of Primary key in general, specifically on condition Tables(A9xx for example) instead of Start-date? appreciate any help!!
Best Regards
TRP

Hmm, another example is CSKS, this logic was probably designed already in the 1980s...maybe it was seen beneficial to be able to select the currently valid record by using the primary key only (the first record where DATBI is larger than system date, not possible when DATAB is the key instead).
Maybe there are better explanations. Why do you need to know this, just curious?
Thomas

How to make a form using a wizard when the table has no primary key ?

Hi,
I want to make a form to update, delete a table. The table has no primary key. The problem is that the Wizard ask for a primary key.
How to avoid using a primary key ? i mean I don't want to create a primary key if is is possible.
I would like to use the wizard; is it possible ?
Thank you for your kind answers.
Christian

I believe the key is choosing 'Interactive' as opposed to 'Classic' in the implementation and then you can choose 'Existing Trigger' for the primary key source and it should work to use an existing column as your proimary key.

Mapping in OWB with primary key and foreign key relationship

Hi all,
I am new to this datawarehousing field. I have just started my career. I have to now create a mapping in owb where a table has a field which is a primary key of another table in the same staging area. If you guys could help me out with the a method it can be created that would be very helpful to me.
I thought of 2 ideas,
1. If I can use a look up, but then I am not sure if i can use a lookup for primary key, foreign key relationship. If I can use also, I do not know how to use that.
2. What if I can directly take that the first table and link the primary key of that table to the second table which uses that primary key of the first table as one of its fields.
I do not know how feasible these methods are. Please guys help me out.
Thanks in advance.

I have a similar case where table a and table b having relation but table a got inserted with data and table b is empty so there no values for foriegn key column in table b to realte with table a.
Now i want to load table b foriegn key with primary key column values of table a.
how can we do this in owb
thanks
kumar

APEX and Primary Keys

Hello:
I ran into a situation where we have a table with no primary key set. When I tried to create a form, APEX told me that a primary key must be set in order to run reports. This makes complete sense. No issue here. For some of our tables, we can set the primary key.
The issue we have is that some of our tables are using "natural primary keys". We have tables where more than one column is designated as a primary key. For example, if I have a table with patient_id, organization_id, insurance_id, and expiration date. In order for a record to be unique in this table both the organization_id and insurance_id are set as primary keys.
If I attempt to create a form in APEX using these tables which have more than one primary key, how will APEX know that there are more than one primary key?
Thanks for the input.

In that case you could also use rowid and instead of views. I have an example showing how
this can be done:
http://apex.oracle.com/pls/otn/f?p=31517:157
Denes Kubicek
http://deneskubicek.blogspot.com/
http://www.opal-consulting.de/training
http://apex.oracle.com/pls/otn/f?p=31517:1
-------------------------------------------------------------------

Replication and Primary Keys

I am investigating replication for a client of mine who needs to have two separate sites inserting and editing data into identical schemas, but would like to sync the two databases on a regular (nightly?) basis. I bought an Oracle Replication book, and from it I have figured I need to implement advanced replication...but I have not found the answer to this question:
How does one handle Primary Keys for new records? The client is currently using sequences on both ends to generate the keys...do I simply set up the sequences so that one site uses 0 to 1 million, and the other site uses 1 million to 2 million, etc?
Or is there a more 'automatic' way that Oracle can handle replication of primary key columns? Maybe by using compound primary keys (ID column and location column)?
Thanks in advance,
Chris DuBuc
Buke Incorporated

For two sites, the easiest is probably to have the sequences on one site generate even keys and the sequences on the other site generate odd keys. For more than that, you'll probably want to give each site a different range of values, but that tends to be more painful to deal with than odd/even.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

Cascade update of primary key in child tables

Hi,
We have a typical scenario in which the primary key has to propage to the child table into 3 levels. We are getting the no parent key exception if we create new data into the three tables using 3 level master detail relationship and execute commit operation. The following is the structure of the tables.
Parent_table (sno number primary key, name varchar2(100));
Child_table (fk_sno number primary key, name varchar2(100), foreign key (fk_sno) references parent_table(sno));
GrandChild_table (sno number primary key, fk_sno number, name varchar2(100), foreign key (fk_sno) references Child_table(fk_sno));
The requirement is to update fk_sno in child_table and grandchild_table with the trigger generated primary key sno in the parent_table.
The application module is having the following structure
parenttable
|
----------childtable
|
-----------grandchild_table
If we create new records into parent_table and child_table it is working fine when we commit the data. If we create another record into grandchild_table and commit data we are getting the foreign key violation exception. We are using composition in the association to update the modified values to refresh the data.
Is there any problem in the data model to use fk_sno as primary key and foreign key in child_table.
Thanks and Regards,
S R Prasad

Hmm, another example is CSKS, this logic was probably designed already in the 1980s...maybe it was seen beneficial to be able to select the currently valid record by using the primary key only (the first record where DATBI is larger than system date, not possible when DATAB is the key instead).
Maybe there are better explanations. Why do you need to know this, just curious?
Thomas

Primary Key & Logical Key in Hierarchy

Am a bit confused with the primary key in Dimensions.....
1. Can anyone explain the use of Primary key and the criteria to define the primary key for a level if the level has more than one level keys....
2. If a level has more than 2 logical keys and both of them are used for drilldown (use for drilldown checked) then what will happen.... lets say we have 2 keys key1 & key2 then which key is used for drilldown in answers.....

1. Can anyone explain the use of Primary key and the criteria to define the primary key for a level if the level has more than one level keys....The level key defines the unique elements in each logical level. The dimension table logical key has to be associated with the lowest level of a dimension and has to be the level key for that level.A logical level can have multiple level keys. When that is the case, specify the key that is the primary key of that level.
2. If a level has more than 2 logical keys and both of them are used for drilldown (use for drilldown checked) then what will happen.... lets say we have 2 keys key1 & key2 then which key is used for drilldown in answers.....With "use for drilldown" checked for 2 logical keys , when you drill form the parent level both the keys will be displayed in the report.
Rgds,
Dpka

Cannot modify value of primary key field after lookup.

I realize this could be a WebSphere problem, but I don't know if it is an EJB problem or what? So I'm posting anyway, and adding Duke Dollars in the hopes someone out there has encountered this.
Okay, I'm using WebSphere Studio Application Developer 4.0.3.
I am using an EJB that has three primary key fields.
I use the primary keys to lookup the bean.
I then want to update the value of one of the primary keys.
So I create a setter and getter method for that primary key field.
I then can call the set method, but it does nothing.
I get no errors.
It compiles.
I rebuild, regenerate access beans, and redeploy and rmic.
I can use ctrl-space to see the functions in the JSP editor.
However, the set function never gets called for some reason, and I get no runtime exception either.
For example, if I do this in my code:
MyBeanFactory myBean = new MyBeanFactory();
MyBeanKey myBeanKey = new MyBean(name,age,city);
MyBean myBean = myBeanFactory.findByPrimaryKey(myBeanKey);
// this function doesn't do anything, because it's a primary key field
// but it does compile and I get no runtime errors
myBean.setCity("Orlando");
// this function works fine, presumably because it isn't a primary key
myBean.setState("Florida");Questions;
Is there a restriction that says I can't update the value of a field if it is marked as a primary key?
If not, what could I be doing wrong?

Looks like your appserver is working as per the specification.
Check this out:
Question
How can I update the primary key field in a CMP Entity Bean?
Derived from
A question posed by Shanks75 shanks75
Topics
Java:API:EJB:EntityBean:CMP, Java:API:EJB:2.0
Author
Tim Duggan
Created
Oct 9, 2001
Answer
You cannot change the primary key field of an Entity bean. Refer to page 130 of the EJB 2.0 specification, it states "Once the
primary key for an entity bean has been set, the Bean Provider must not attempt to change it by use of set accessor methods
on the primary key cmp-fields. The Bean provider should therefore not expose the set accessor methods for the primary key
cmp-fields in the component interface of the entity bean."
A work around to update a primary key field, would be to remove and then an re-create the bean.
taken from here:
http://www.jguru.com/faq/view.jsp?EID=515864

Master Detail Forms with 2 composite primary keys - Is there a workaround?

Hello All,
I have been searching for a workaround to the maximum 2 part primary key restriction on the multi-row updates, and master-detail forms, and am hoping that someone can help me. I am using HTMLDB v2.0.0.00.49 with IE 6 against a 9.2 DB.
I successfully implemented the workaround of Fred Stoopendaal's (see Updata PK on HTML DB ) and it works fine for single page multi-record updateable forms, but alas I haven't been able to extend it to master detail forms (I think it is something to do with Oracle not allowing the "returning" clause on views).
Here is what I tried:
two tables, one with a 2 part composite primary key, which is the master table, and a detail table with 3 part composite primary key -
--------- BEGIN SQL ---------
create table master_table
( master_col1 number
, master_col2 number
, master_col3 varchar2(30)
, constraint master_pk primary key (master_col1,master_col2));
create table detail_table
(detail_col1 number
,detail_col2 number
,detail_col3 number
,detail_col4 varchar2(30)
, constraint detail_pk primary key(detail_col1,detail_col2,detail_col3)
, constraint master_detail_fk foreign key (detail_col1,detail_col2) references master_table(master_col1,master_col2));
create or replace view v_master_table as
select rowid mata_rowid,mata.*
from master_table mata;
create or replace view v_detail_table as
select rowid deta_rowid,
(select rowid from master_table mata where mata.master_col1 = deta.detail_col1 and mata.master_col2 = deta.detail_col2) deta_mata_rowid
, deta.*
from detail_table deta;
create or replace trigger mata_ins_upd_trg
instead of insert or update on v_master_table
referencing new as new old as old
for each row
begin
if inserting then
insert into master_table (master_col1, master_col2, master_col3)
values (:new.master_col1, :new.master_col2, :new.master_col3);
end if;
if updating then
update master_table
set master_col1 = :new.master_col1,
master_col2 = :new.master_col2,
master_col3 = :new.master_col3
where rowid = :old.mata_rowid;
end if;
end;
create or replace trigger deta_ins_upd_trg
instead of insert or update on v_detail_table
referencing new as new old as old
for each row
begin
if inserting then
insert into detail_table ( detail_col1, detail_col2, detail_col3, detail_col4)
values (:new.detail_col1, :new.detail_col2, :new.detail_col3, :new.detail_col4);
end if;
if updating then
update detail_table
set detail_col1 = :new.detail_col1,
detail_col2 = :new.detail_col2,
detail_col3 = :new.detail_col3,
detail_col4 = :new.detail_col4
where rowid = :old.deta_rowid;
end if;
end;
--------- END SQL ---------
Then I created a master-detail form in Apex on the two views, using the mata_rowid and deta_rowid as primary keys, and mata_rowid=deta_mata_rowid as the link. I realise that using a function to fetch the master rowid within the detail view query is costly, but it was my intention to modify the record fetch queries to use the real FK columns once things were up and running.
It seems to generate the pages ok, and I can insert/update master table records, but as soon as I modify records in the detail table things go a bit haywire. I can't find any documentation on how the inbuilt MRU/MRD logic works, so can't figure out the issue.
Can anyone out there tell me what the problem is with the logic above, or if they have come up with a neat solution to this annoying limitation. I know that many will say that I should modify the data model to use surrogate primary keys, but many of the uses for HTMLDB are new interfaces for old schemas, so a workaround that doesn't involve wholesale data model changes would be preferable.
Thanks in advance,
Mike Cretan

Hi, this is likely not the most elegant way...but perhaps the simplest -- and I didn't have much time to play.
I used Wizard to create two separate Master Detail forms, each with a separate detail table. Thus I ended up with four pages:
Page "A" - "Selector" page for Master (Report), with Edit link driving to Detail-1
Page "B" - Editable Master/Detail-1 page (HTML / Report)
Page "C" - "Selector" page for Master (Report), with Edit link driving to Detail-2
Page "D" - Editable Master/Detail-2 page (HTML / Report)
Then I selected the primary key column TWICE on the Report on Page A. Modified the second instance of this column to navigate to Page D (passing primary key) exactly the way the original instance of this column navigates to Page B. Then I deleted Page C.
Since you can have only one Tabular Entry form per page, this seemed the best way to drive two separate detail tables from a common interface.

Use of primary key

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