Hiding columns or foreign keys to make a structural diagram less busy

Is this possible?

When some columns are not displayed in the diagram, I would suggest adding a section at the bottom similar to where indexes are displayed and adding some verbage like "Some columns are not displayed" as a fine print, an alert for seeing eyes :-)
Thanks a million Philip.
It has been a long while since I checked the features requested/status page. I will see if some of my other thoughts will be covered infuture releases.

Similar Messages

Determine if database view column is foreign key in underlying table

Hi,
I have posted this same question to the General Database Discussions and JDBC forums.
I am using Oracle database 10g (10.1.0.4.0 - 64 bit production) standard edition on Red Hat Enterprise Linux AS release 3, JDK 1.4.2 and the latest Oracle JDBC (thin) driver.
We have a java GUI application that is a front-end for our database. Some of the data entry screens display data from database views. If a column in the view is a foreign key in the underlying table, we want to display a combo-box with the valid values so that the user can choose a correct value.
Is there some way to know whether a column in a view is a foreign key in the view's underlying table?
Thanks,
Avi.

I take that back.. I did figure something out for ya.. After reading some elses post I wrote this code... but its time to go home... I believe this will show you all the constraints and constraint types for the underlying tables of all the views for a user. You can mess with it and get it to return only FK (constraint_type = 'R') and only for a single view if ya like... The all_dependencies data dictionary view is the key to this whole operation...
select con.table_name, ucc.column_name, con.constraint_name, con.constraint_type
from all_constraints con, all_cons_columns ucc
where con.owner = user and
con.owner = ucc.owner and
con.table_name = ucc.table_name and
con.table_name in
(SELECT referenced_name
FROM all_dependencies
WHERE referenced_owner = USER
AND referenced_type = 'TABLE'
AND type = 'VIEW');

Foreign key primary relationship

Can we create foreign key on composite primary key? how?
Edited by: 854624 on Apr 25, 2011 8:30 PM

Hi,
854624 wrote:
But can we relate one column as foreign key with composite primary key ?Sorry, I don't understand what you're asking. Please post a concrete example, like
"If I have these tables: CREATE TABLE ...
and they contain this data: ...
can I have a foreign key constraint that would allow these statements: INSERT ...
but not allow these: INSERT ...
because ...?"
In the referenced table, the column for a foreign key must be unique. If column_a is unique, then it can be part of a composite primary key, but it doesn't make any sense. if column_a is unique, why isn't column_a, all by itself, the primary key?

Does a foreign key have to be a primary key

Hey all.I was checking on the database code written by sambapos.To my surprise, I found a foreign key that is not a primary key anywhere.
Is that possible?
If, so why?
I am really astonished.

Limitations and Restrictions
A foreign key constraint does not have to be linked only to a primary key constraint in another table; it can also be defined to reference the columns of a UNIQUE constraint in another table.
When a value other than NULL is entered into the column of a FOREIGN KEY constraint, the value must exist in the referenced column; otherwise, a foreign key violation error message is returned. To make sure that all values of a composite foreign key constraint
are verified, specify NOT NULL on all the participating columns.
FOREIGN KEY constraints can reference only tables within the same database on the same server. Cross-database referential integrity must be implemented through triggers. For more information, see
CREATE TRIGGER (Transact-SQL).
FOREIGN KEY constraints can reference another column in the same table. This is referred to as a self-reference.
A FOREIGN KEY constraint specified at the column level can list only one reference column. This column must have the same data type as the column on which the constraint is defined.
A FOREIGN KEY constraint specified at the table level must have the same number of reference columns as the number of columns in the constraint column list. The data type of each reference column must also be the same as the corresponding column in the column
list.
The Database Engine does not have a predefined limit on either the number of FOREIGN KEY constraints a table can contain that reference other tables, or the number of FOREIGN KEY constraints that are owned by other tables that reference a specific table.
Nevertheless, the actual number of FOREIGN KEY constraints that can be used is limited by the hardware configuration and by the design of the database and application. We recommend that a table contain no more than 253 FOREIGN KEY constraints, and that it
be referenced by no more than 253 FOREIGN KEY constraints.
FOREIGN KEY constraints are not enforced on temporary tables.
If a foreign key is defined on a CLR user-defined type column, the implementation of the type must support binary ordering. For more information, see
CLR User-Defined Types.
A column of type varchar(max) can participate in a FOREIGN KEY constraint only if the primary key it references is also defined as type
varchar(max).
Read this article
http://msdn.microsoft.com/en-us/library/ms189049.aspx
Regards, Ashwin Menon My Blog - http:\\sqllearnings.com

ADF Toplink Create Row with foreign key

Hello,
I'd like to create a new row in a table that has a required one-to-one mapping relationship (foreign key). I've created an edit form by dragging the return node of a readQuery. The columns holding foreign key values aren't added to the page(because of 1-1 relationship) and when I commit the changes errors are raised.
How do I pass the foreign key to the ADF Toplink framwork to include in the insert statement.

TopLink's persistence model is based around relationships, which represent FKs. To have these FKs properly populated you need to create the corresponding object relationships.
To do this you need to create a data action that will invoke a method on your class passing in the object you want to create the relationship with. There is currently an issue where ADF will not allow you to easily drop a set method onto an action. You will need to create a method on your bean that does not start with 'set'.
In the demos I have done I have added a method like 'populateAddress(Address)' that internally calls the set method. This populate method will show up on the data control palette and you can then drop it on the action in your page flow.
One additional tip: To access the object you want to pass in you will need to extend the default expression that reflects the current selected row in the iterator to have '.dataProvider' appended. This accesses the persistent object within row container.
If you are still struggling please contact me through the email address in my forum profile.
Doug

New SQL Developer Data Modeler : name of attributes of foreign key

Hi,
with designer the name of column of foreign key was the " short name of entity/table master" + "_" + "the name of column attribute of the master table" .
Instead in the sql developer D.M. the system uses directly the name of the column/attribute of the master table and if the name exists in the slave table it uses a number to distinguish them .
So, if i have a table with short name gp and a primmary key id and a slave table with even a column id ,
with the D.M i'll have in the slave table a column named id2; in the designer instead the new column is gp_id .
Is possible to have the same behavior of designer even in the SQL Developer Data Modeler ?
Regards
Gianpaolo Giliberto

Hi Gianpaolo,
the columns of foreign keys are generated without the short name of master tablehow do you define that short name? Table and column have property "Abbreviation" - short name should be set there. You need also to set naming templates in "General Options>Naming Standard>Templates". Templates will be used when foreign key is created or you can apply them in Table dialog or for whole relational model using pop-up menu in the browser.
no foreign key index is generated on foreign key columns I assume, you want it for DDL generation only - this is controlled in "General Options>DDL"
Regards,
Philip

Can I create a foreign key when creating Business Components from Tables

Hi,
I would like to use ADF and JSF to create an application on our database. My problem is our database does not "conform". i.e. there are no foreign key constraints.
When I create a "Business Component from Tables" view, can I put in my own joins between tables so enabling the use of the generated views?
Jon L.

View object instances show up in the data control palette once you've added them to your application module's data model.
See these sections in the ADF Developer's Guide for more information:
Section 2.6.3, "Using View Objects in the Application Module's Data Model" talks about using view object instance in the data model as part of the overview chapter.
Section 4.5, "Understanding the Active Data Model" explains a little more about this
Section 5.3, "Using a View Object in an Application Module's Data Model" shows how to do this.
Chapter 10, "Overview of Application Module Data Binding" gives details on how the application and its view objects are exposed in the Data Control palette.
You can find the guide on the ADF Learning Center on OTN.
http://www.oracle.com/technology/products/adf/learnadf.html
Look for the ADF Developer's Guide for Forms/4GL Developers.

Foreign key constraint on multi-column primary key accepts 1 empty column!?

Hi, we have a reference table with a two-column primary key. In the child table there is a non-mandatory foreign key constraint to this table. So if both child columns are null it's ok too. But now we see that if one of the two child table columns that build up the foreign key is null, the other column can have any (non-existant in the master-tabel) value you like!? That does not make sense.
Can anyone explain this to me???
Regards, Paul.

Paul, I believe that this is in accordance to the ANSI SQL standard requirement for the treatment of nulls in a multi-column FK. In any case Oracle specifically states this is the way FK work From the 10 Concepts manual, Ch 21 Data Integrity, topic Nulls and Foreign Keys:
The relational model permits the value of foreign keys either to match the referenced primary or unique key value, or be null. If any column of a composite foreign key is null, then the non-null portions of the key do not have to match any corresponding portion of a parent key. <<HTH -- Mark D Powell --

Foreign Key To More Than One Column

Hi Guys,
I have a requirement like below
I have 3 tables (Prospect,customer,user) and I have a contact_dtls table .
In prospect table Prospect_id is the primary like this customer_id in customer table and user_id in the user table
in the contact_dtls table I have a column contact_id and other cols.The contact_id can be from prospect_id,customer_id and user_id in other words we can tell the prospect can be a contact or the customer can be a contact and the user also can be a contact also.Now the question is "is it possible to maintain primary key and foreign key relationship with this design that means the prospect_id,customer_id and user_id would be the foreign keys to the contact_dtls table
I am using oracle11g Version

Hello,
as it has been said in the previous reply, you cannot have a foreign key on multiple tables. Maybe you can create a new table contacts containing at least an id column. This table will be parent to prospect, customer and user. Now contact_dtls.customer_id can reference the contacts.id column.
This will also make sure, that the ids from prospect, customer and user are unique. It even will be possible that a contact is user and customer at the same time.
Regards
Marcus
Edited by: Marwim on 16.11.2012 10:59

How can I have multiple instances of a column that itself holds a foreign key reference?

I am new to Visual Studio so to start learning it I first of all downloaded a sample available at https://code.msdn.microsoft.com/ADPNET-Entity-Framework-2d1160cb and started working around it. Since I have fairly good knowledge of VB6 and SQL it did
not take much time for me to understand the whole pattern the sample is based on. Had Microsoft given a detail explanation or a walk through of the sample it would have been much easier to understand the basics. However, I somehow managed to work around it
and have build a small desktop application in wpf using Entity Framework and MVVM. But a point has come where I have got completely stuck up finding no way out. The problem is as under:
I have two tables. 1 Advocate and 2 Party. Table Advocate would contain names of advocates and would have a primary key. Similarly Party would have names and their respective primary keys.
Then I have another two tables 1. Case and 2 CaseDetail. Table Case would simply hold three columns: 1. CaseId 2. CaseNo and 3. Year. Table CaseDetail would have CaseDetailId as a primary key the CaseId as a Foreign Key. Now what I need is that a particular
case could have multiple advocates and multiple petitioners. So the table CaseDetail would have two columns to hold advocateId and PartyId as a Foreign Keys.
If you look at the sample referred above you would not find how to deal with such a case. When I follow the pattern of the sample I get host of design time and runtime errors.
Therefore, please suggest what strategy should be adopted in a scenario described above while developing WPF application using Entity Framework and MVVM.

I am new to Visual Studio so to start learning it I first of all downloaded a sample available at https://code.msdn.microsoft.com/ADPNET-Entity-Framework-2d1160cb and started working around it. Since I have fairly good knowledge of VB6 and SQL it did not
take much time for me to understand the whole pattern the sample is based on. Had Microsoft given a detail explanation or a walk through of the sample it would have been much easier to understand the basics. However, I somehow managed to work around it and
have build a small desktop application in wpf using Entity Framework and MVVM. But a point has come where I have got completely stuck up finding no way out. The problem is as under:
I have two tables. 1 Advocate and 2 Party. Table Advocate would contain names of advocates and would have a primary key. Similarly Party would have names and their respective primary keys.
Then I have another two tables 1. Case and 2 CaseDetail. Table Case would simply hold three columns: 1. CaseId 2. CaseNo and 3. Year. Table CaseDetail would have CaseDetailId as a primary key the CaseId as a Foreign Key. Now what I need is that a particular
case could have multiple advocates and multiple petitioners. So the table CaseDetail would have two columns to hold advocateId and PartyId as a Foreign Keys.
If you look at the sample referred above you would not find how to deal with such a case. When I follow the pattern of the sample I get host of design time and runtime errors.
Therefore, please suggest what strategy should be adopted in a scenario described above while developing WPF application using Entity Framework and MVVM.

Two columns in the same table that are foreign keys to the same master key

i want to create a table let say X, which have two columns that are foreign key that reference the same column in the master table, so does this count as bad database design.

here is the full ddl for the two table, where in the second table there are two columns that represent the primary key and they are also two foreign keys to the same columns in the master table (items)
Desc item table;
Item_id
Item_name
Item_price
Item_quantitiy
Create table item_recommendation ( item_id varchar(20), recommended_item varchar(20),
CONSTRAINT recom_primary PRIMARY KEY (item_id, recommended_item),
CONSTRAINT F1 FOREIGN KEY (item_id) REFERENCES items(item_id), ),
CONSTRAINT F2 FOREIGN KEY (recommended_item) REFERENCES items(item_id));

Primary key and Foreign key on same column

Hi, I am able to create below tables , primary and foreign keys as below.
But Is this valid design? Can I define a column (ckey2 in table "child") as
primary key and as well as foreign key?
CREATE TABLE parent (
col1 NUMBER,
col2 NUMBER
CREATE TABLE child (
ckey1 NUMBER,
ckey2 NUMBER,
ckey3 NUMBER
alter table parent add constraint parent_pk primary key( col1 );
alter table child add constraint child_pk primary key( ckey2 );
alter table child add constraint child_fk foreign key( ckey2 ) references parent( col1);
Thanks.

Can I define a column (ckey2 in table "child") as primary key and as well as foreign key?You mean you want to define a one-to-one relationship between parent and child tables.. why would you want to do that ? You might as well merge the 2 tables into one.

How to fetch column data using foreign key in adf table ?

I have created a adf table using a view that has a group id and user id column. I want to display the user name ( from user table) and group name from group table. I had created view links to the corresponding tables from the user_group view ( whose iterator is used to render the table).
It sort of works. I dragged the user name from the embedded user iterator in user_group iterator. It does find the correct user name but if I have more than one row, it displays the user name of the last row user in all rows !
Is there a solution to this problem ?

Well, I saw in the view query for the association view ( for Many-Many) that the SQL already had the joins with the two ( master) tables to the association table. So I went ahead and added the descriptive columns to the select clause. Then the selected columns showed up in the attribute list by themselves ( without my intervention). So far so good.
Then I recreated the adf table attribute by dragging these newly selected attribute to the page. I still see that the value of the attribute is the same in all the rows - this time it is the value for the FIRST row. It doesn't correspond to the foreign key for that particular row.
IS THIS A BUG ? Has anyone else ever done this ?

Foreign keys to same table / Who columns in User table???

Hi All,
We are designing a database for our client and we are using common columns in all tables like CreatedBy and UpdatedBy which are foreign keys to USER table. My question is can we use these two columns in USER table and have the foreign key constraints to the same tables?
USER table script will look like following..
CREATE TABLE XX_USER
     User_ID                              VARCHAR2(10)
,     CreatedBy                         NUMBER(10)
,     UpdatedBy                         NUMBER(10)
,     User_Name                         VARCHAR2(100)     NOT NULL
,     Designation                         VARCHAR2(100)     NOT NULL
,     CONSTRAINT USER_ISACTIVE_CHECK CHECK (Is_Active in ('Y', 'N'))
,     CONSTRAINT USER_KEY PRIMARY KEY (User_ID),
,     CONSTRAINT USER_CREATED_BY FOREIGN KEY (CREATED_BY)
     REFERENCES XX_USER (USER_ID)
,     CONSTRAINT USER_UPDATED_BY FOREIGN KEY (UPDATED_BY)
     REFERENCES XX_USER (USER_ID)
);I think what I am doing (the above script) is not correct. Could someone please suggest me how can solve this issue?
Thanks in advance,
Oraebs

user8644385 wrote:
We are designing a database for our client and we are using common columns in all tables like CreatedBy and UpdatedBy which are foreign keys to USER table. My question is can we use these two columns in USER table and have the foreign key constraints to the same tables?You can. After fixing synatx errors:
SQL> CREATE TABLE XX_USER
2 (
3   User_ID        VARCHAR2(10)
4 , CreatedBy     NUMBER(10)
5 , UpdatedBy     NUMBER(10)
6 , User_Name     VARCHAR2(100) NOT NULL
7 , Designation   VARCHAR2(100) NOT NULL
8 , Is_Active     VARCHAR2(1)
9 , CONSTRAINT USER_ISACTIVE_CHECK CHECK (Is_Active in ('Y', 'N'))
10 , CONSTRAINT USER_KEY PRIMARY KEY (User_ID)
11 , CONSTRAINT USER_CREATED_BY FOREIGN KEY (CreatedBy)
12       REFERENCES XX_USER(USER_ID)
13 , CONSTRAINT USER_UPDATED_BY FOREIGN KEY (UpdatedBy)
14       REFERENCES XX_USER(USER_ID)
15 )
16 /
Table created.
SQL> Now USER_ID is a string while CreatedBy/UpdatedBy is a number. Even though it is allowed, it limits USER_ID to numeric strings and causes implicit conversions while validating. So I would change CreatedBy/UpdatedBy data type to VARCHAR2(10).
SY.

Foreign Key columns

hi, Does SQL Developer can show you the columns of a table involved in a foreign constraint? I can see in the DB tree the tables, then the constraints and I can see the table referenced but not the columns.
Is there anyway to see them? (I'm used to work with TOAD but I'm evaluating the posibility to migrate to SQL Developer)
Thanks

It's not very intuitive, but the only place I have seen the foreign key constraint columns listed in the UI is in the Edit Table dialog (short of generating the DDL or writing your own query to run in the worksheet).
To log an enhancement request to get this added, use the link in the "Feature Requests" sticky thread.
To do it yourself (ie not wait for the development team), you could write an extension to add a custom Constraints tab to the Tables information that displays the columns for the currently selected constraint.
theFurryOne

Hiding columns or foreign keys to make a structural diagram less busy

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