Finding foreign key constraints in sql server

Thu, Feb 2, 2012 1-minute read

Sometimes when trying to truncate a table you need to remove all foreign keys referencing that table and that can be hard to do, since you cannot get a nice graphical overview.

To get the list of foreign key constraints for a given table you can run the following script exchanging the value in the @TABLENAME parameter.

DECLARE @TABLENAME VARCHAR(100);
SET @TABLENAME='';

SELECT
    K_Table = FK.TABLE_NAME,
    FK_Column = CU.COLUMN_NAME,
    PK_Table = PK.TABLE_NAME,
    PK_Column = PT.COLUMN_NAME,
    Constraint_Name = C.CONSTRAINT_NAME
FROM
    INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
    ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
    ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
    ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
            SELECT
                i1.TABLE_NAME,
                i2.COLUMN_NAME
            FROM
                INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
            INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
                ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
            WHERE
                i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
           ) PT
    ON PT.TABLE_NAME = PK.TABLE_NAME
    
    WHERE PK.TABLE_NAME[email protected]TABLENAME

Enjoy :)