Friday, September 23, 2011

Query to Display Foreign Key Relationships and Name of the Constraint for Each Table in Database

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
---- optional:
ORDER BY
1,2,3,4
WHERE PK.TABLE_NAME='something'WHERE FK.TABLE_NAME='something'
WHERE PK.TABLE_NAME IN ('one_thing', 'another')
WHERE FK.TABLE_NAME IN ('one_thing', 'another')




or
Rewritten the query to be slightly faster:


SELECT
CONSTRAINT_NAME = REF_CONST.CONSTRAINT_NAME,
TABLE_CATALOG = FK.TABLE_CATALOG,
TABLE_SCHEMA = FK.TABLE_SCHEMA,
TABLE_NAME = FK.TABLE_NAME,
COLUMN_NAME = FK_COLS.COLUMN_NAME,
REFERENCED_TABLE_CATALOG = PK.TABLE_CATALOG,
REFERENCED_TABLE_SCHEMA = PK.TABLE_SCHEMA,
REFERENCED_TABLE_NAME = PK.TABLE_NAME,
REFERENCED_COLUMN_NAME = PK_COLS.COLUMN_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS REF_CONST
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
ON REF_CONST.CONSTRAINT_CATALOG = FK.CONSTRAINT_CATALOG
AND REF_CONST.CONSTRAINT_SCHEMA = FK.CONSTRAINT_SCHEMA
AND REF_CONST.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
AND FK.CONSTRAINT_TYPE = ‘FOREIGN KEY’
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON REF_CONST.UNIQUE_CONSTRAINT_CATALOG = PK.CONSTRAINT_CATALOG
AND REF_CONST.UNIQUE_CONSTRAINT_SCHEMA = PK.CONSTRAINT_SCHEMA
AND REF_CONST.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
AND PK.CONSTRAINT_TYPE = ‘PRIMARY KEY’
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE FK_COLS ON REF_CONST.CONSTRAINT_NAME = FK_COLS.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE PK_COLS ON PK.CONSTRAINT_NAME = PK_COLS.CONSTRAINT_NAME

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