How to find foreign key references in a table [duplicate] - database

Question

In Oracle SQL Developer, if I'm viewing the information on a table, I can view the constraints, which let me see the foreign keys (and thus which tables are referenced by this table), and I can view the dependencies to see what packages and such reference the table. But I'm not sure how to find which tables reference the table.
For example, say I'm looking at the emp table. There is another table emp_dept which captures which employees work in which departments, which references the emp table through emp_id, the primary key of the emp table. Is there a way (through some UI element in the program, not through SQL) to find that the emp_dept table references the emp table, without me having to know that the emp_dept table exists?

Answer 1

No. There is no such option available from Oracle SQL Developer.
You have to execute a query by hand or use other tool (For instance PLSQL Developer has such option). The following SQL is that one used by PLSQL Developer:
select table_name, constraint_name, status, owner
from all_constraints
where r_owner = :r_owner
and constraint_type = 'R'
and r_constraint_name in
(
select constraint_name from all_constraints
where constraint_type in ('P', 'U')
and table_name = :r_table_name
and owner = :r_owner
)
order by table_name, constraint_name
Where r_owner is the schema, and r_table_name is the table for which you are looking for references. The names are case sensitive
Be careful because on the reports tab of Oracle SQL Developer there is the option "All tables / Dependencies" this is from ALL_DEPENDENCIES which refers to "dependencies between procedures, packages, functions, package bodies, and triggers accessible to the current user, including dependencies on views created without any database links.". Then, this report have no value for your question.

Answer 2

To add this to SQL Developer as an extension do the following:
Save the below code into an xml file (e.g. fk_ref.xml):
<items>
<item type="editor" node="TableNode" vertical="true">
<title><![CDATA[FK References]]></title>
<query>
<sql>
<![CDATA[select a.owner,
a.table_name,
a.constraint_name,
a.status
from all_constraints a
where a.constraint_type = 'R'
and exists(
select 1
from all_constraints
where constraint_name=a.r_constraint_name
and constraint_type in ('P', 'U')
and table_name = :OBJECT_NAME
and owner = :OBJECT_OWNER)
order by table_name, constraint_name]]>
</sql>
</query>
</item>
</items>
Add the extension to SQL Developer:
Tools > Preferences
Database > User Defined Extensions
Click "Add Row" button
In Type choose "EDITOR", Location is where you saved the xml file above
Click "Ok" then restart SQL Developer
Navigate to any table and you should now see an additional tab next to SQL one, labelled FK References, which displays the new FK information.
Reference
http://www.oracle.com/technetwork/issue-archive/2007/07-jul/o47sql-086233.html

Answer 3

Replace [Your TABLE] with emp in the query below
select owner,constraint_name,constraint_type,table_name,r_owner,r_constraint_name
from all_constraints
where constraint_type='R'
and r_constraint_name in (select constraint_name
from all_constraints
where constraint_type in ('P','U')
and table_name='[YOUR TABLE]');

Answer 4

You may be able to query this from the ALL_CONSTRAINTS view:
SELECT table_name
FROM ALL_CONSTRAINTS
WHERE constraint_type = 'R' -- "Referential integrity"
AND r_constraint_name IN
( SELECT constraint_name
FROM ALL_CONSTRAINTS
WHERE table_name = 'EMP'
AND constraint_type IN ('U', 'P') -- "Unique" or "Primary key"
);

Answer 5

SQL Developer 4.1, released in May of 2015, added a Model tab which shows table foreign keys which refer to your table in an Entity Relationship Diagram format.

Answer 6

SELECT DISTINCT table_name,
constraint_name,
column_name,
r_table_name,
position,
constraint_type
FROM (SELECT uc.table_name,
uc.constraint_name,
cols.column_name,
(SELECT table_name
FROM user_constraints
WHERE constraint_name = uc.r_constraint_name) r_table_name,
(SELECT column_name
FROM user_cons_columns
WHERE constraint_name = uc.r_constraint_name
AND position = cols.position) r_column_name,
cols.position,
uc.constraint_type
FROM user_constraints uc
inner join user_cons_columns cols
ON uc.constraint_name = cols.constraint_name
WHERE constraint_type != 'C')
START WITH table_name = '&&tableName'
AND column_name = '&&columnName'
CONNECT BY NOCYCLE PRIOR table_name = r_table_name
AND PRIOR column_name = r_column_name;

Answer 7

This has been in the product for years - although it wasn't in the product in 2011.
But, simply click on the Model page.
Make sure you are on at least version 4.0 (released in 2013) to access this feature.

Answer 8

How about something like this:
SELECT c.constraint_name, c.constraint_type, c2.constraint_name, c2.constraint_type, c2.table_name
FROM dba_constraints c JOIN dba_constraints c2 ON (c.r_constraint_name = c2.constraint_name)
WHERE c.table_name = <TABLE_OF_INTEREST>
AND c.constraint_TYPE = 'R';

Answer 9

To add to the above answer for sql developer plugin, using the below xml will help in getting the column associated with the foreign key.
<items>
<item type="editor" node="TableNode" vertical="true">
<title><![CDATA[FK References]]></title>
<query>
<sql>
<![CDATA[select a.owner,
a.constraint_name,
a.table_name,
b.column_name,
a.status
from all_constraints a
join all_cons_columns b ON b.constraint_name = a.constraint_name
where a.constraint_type = 'R'
and exists(
select 1
from all_constraints
where constraint_name=a.r_constraint_name
and constraint_type in ('P', 'U')
and table_name = :OBJECT_NAME
and owner = :OBJECT_OWNER)
order by table_name, constraint_name]]>
</sql>
</query>
</item>
</items>

Answer 10

I like to do this with a straight SQL query, rather than messing about with the SQL Developer application.
Here's how I just did it. Best to read through this and understand what's going on, so you can tweak it to fit your needs...
WITH all_primary_keys AS (
SELECT constraint_name AS pk_name,
table_name
FROM all_constraints
WHERE owner = USER
AND constraint_type = 'P'
)
SELECT ac.table_name || ' table has a foreign key called ' || upper(ac.constraint_name)
|| ' which references the primary key ' || upper(ac.r_constraint_name) || ' on table ' || apk.table_name AS foreign_keys
FROM all_constraints ac
LEFT JOIN all_primary_keys apk
ON ac.r_constraint_name = apk.pk_name
WHERE ac.owner = USER
AND ac.constraint_type = 'R'
AND ac.table_name = nvl(upper(:table_name), ac.table_name)
ORDER BY ac.table_name, ac.constraint_name
;

Answer 11

Only Replace table_name with your primary table name
select *
from all_constraints
where r_constraint_name in (
select constraint_name
from all_constraints
where table_name='table_name'
);

Answer 12

Replace MY_OWNER_NAME and MY_TABLE_NAME below and you are ready to go RECURSIVELY:
DECLARE
FUNCTION list_all_child_tables_and_constraints(asked_table_name in VARCHAR2, parent_table_name in VARCHAR2)
RETURN VARCHAR2 IS
current_path VARCHAR2(100);
BEGIN
FOR item IN
(SELECT fk.TABLE_NAME, constraint_parent.FK FK1, constraint_child.FK FK2
FROM all_constraints fk, all_constraints pk,
(SELECT acc.CONSTRAINT_NAME, LISTAGG(acc.COLUMN_NAME, ', ') WITHIN GROUP (ORDER BY acc.COLUMN_NAME) AS FK
FROM ALL_CONS_COLUMNS acc
WHERE acc.OWNER = 'MY_OWNER_NAME'
GROUP BY acc.CONSTRAINT_NAME) constraint_parent,
(SELECT acc.CONSTRAINT_NAME, LISTAGG(acc.COLUMN_NAME, ', ') WITHIN GROUP (ORDER BY acc.COLUMN_NAME) AS FK
FROM ALL_CONS_COLUMNS acc
WHERE acc.OWNER = 'MY_OWNER_NAME'
GROUP BY acc.CONSTRAINT_NAME) constraint_child
WHERE pk.owner = fk.r_owner
AND pk.constraint_name = fk.r_constraint_name
AND fk.constraint_type = 'R'
AND pk.table_name = asked_table_name
AND constraint_parent.CONSTRAINT_NAME = fk.CONSTRAINT_NAME
AND constraint_child.CONSTRAINT_NAME = fk.R_CONSTRAINT_NAME
AND pk.owner = 'MY_OWNER_NAME'
AND fk.owner = 'MY_OWNER_NAME')
LOOP
current_path := parent_table_name || ' // ' || item.TABLE_NAME;
DBMS_OUTPUT.PUT_LINE(current_path);
DBMS_OUTPUT.PUT_LINE(' [' || item.FK1 || '] [' || item.FK2 || ']');
DBMS_OUTPUT.PUT_LINE('');
current_path := list_all_child_tables_and_constraints(item.TABLE_NAME, current_path);
END LOOP;
RETURN '-----------FINISHED-----------';
EXCEPTION
WHEN OTHERS THEN
RETURN '-----------FINISHED-----------';
END list_all_child_tables_and_constraints;
BEGIN
DBMS_OUTPUT.PUT_LINE(list_all_child_tables_and_constraints('MY_TABLE_NAME', ''));
END;