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How can I find out what FOREIGN KEY constraint references a table in SQL Server?

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Where can I find foreign key dependencies in SQL Server?

You can Use INFORMATION_SCHEMA. KEY_COLUMN_USAGE and sys. foreign_key_columns in order to get the foreign key metadata for a table i.e. Constraint name, Reference table and Reference column etc.

How do you find all tables that have foreign keys that reference particular table column?

To see foreign key relationships of a table: SELECT TABLE_NAME, COLUMN_NAME, CONSTRAINT_NAME, REFERENCED_TABLE_NAME, REFERENCED_COLUMN_NAME FROM INFORMATION_SCHEMA. KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_SCHEMA = 'db_name' AND REFERENCED_TABLE_NAME = 'table_name';


Here it is:

SELECT 
   OBJECT_NAME(f.parent_object_id) TableName,
   COL_NAME(fc.parent_object_id,fc.parent_column_id) ColName
FROM 
   sys.foreign_keys AS f
INNER JOIN 
   sys.foreign_key_columns AS fc 
      ON f.OBJECT_ID = fc.constraint_object_id
INNER JOIN 
   sys.tables t 
      ON t.OBJECT_ID = fc.referenced_object_id
WHERE 
   OBJECT_NAME (f.referenced_object_id) = 'YourTableName'

This way, you'll get the referencing table and column name.

Edited to use sys.tables instead of generic sys.objects as per comment suggestion. Thanks, marc_s


Another way is to check the results of

sp_help 'TableName'

(or just highlight the quoted TableName and press ALT+F1)

With time passing, I just decided to refine my answer. Below is a screenshot of the results that sp_help provides. A have used the AdventureWorksDW2012 DB for this example. There is numerous good information there, and what we are looking for is at the very end - highlighted in green:

enter image description here


Try this

SELECT
  object_name(parent_object_id) ParentTableName,
  object_name(referenced_object_id) RefTableName,
  name 
FROM sys.foreign_keys
WHERE parent_object_id = object_id('Tablename')

I found this answer quite simple and did the trick for what I needed: https://stackoverflow.com/a/12956348/652519

A summary from the link, use this query:

EXEC sp_fkeys 'TableName'

Quick and simple. I was able to locate all the foreign key tables, respective columns and foreign key names of 15 tables pretty quickly.

As @mdisibio noted below, here's a link to the documentation that details the different parameters that can be used: https://docs.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sp-fkeys-transact-sql


Here is the best way to find out Foreign Key Relationship in all Database.

exec sp_helpconstraint 'Table Name'

and one more way

select * from INFORMATION_SCHEMA.KEY_COLUMN_USAGE where TABLE_NAME='Table Name'
--and left(CONSTRAINT_NAME,2)='FK'(If you want single key)

I am using this script to find all details related to foreign key. I am using INFORMATION.SCHEMA. Below is a SQL Script:

SELECT 
    ccu.table_name AS SourceTable
    ,ccu.constraint_name AS SourceConstraint
    ,ccu.column_name AS SourceColumn
    ,kcu.table_name AS TargetTable
    ,kcu.column_name AS TargetColumn
FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu
    INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc
        ON ccu.CONSTRAINT_NAME = rc.CONSTRAINT_NAME 
    INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE kcu 
        ON kcu.CONSTRAINT_NAME = rc.UNIQUE_CONSTRAINT_NAME  
ORDER BY ccu.table_name