How to find foreign key dependencies in SQL Server?

Question

How can I find all of the foreign key dependencies on a particular column?

What are the different alternatives (graphically in SSMS, queries/views in SQL Server, 3rd party database tools, code in .NET)?

Answer 1

One that I really like to use is called SQL Dependency Tracker by Red Gate Software. You can put in any database object(s) such as tables, stored procedures, etc. and it will then automatically draw the relationship lines between all the other objects that rely on your selected item(s).

Gives a very good graphical representation of the dependencies in your schema.

Answer 2

The following query will help to get you started. It lists all Foreign Key Relationships within the current 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

You can also view relationships graphically within SQL Server Management studio within Database Diagrams.

Answer 3

try: sp_help [table_name]

you will get all information about table, including all foreign keys

Answer 4

I think this script is less expensive:

SELECT f.name AS ForeignKey, OBJECT_NAME(f.parent_object_id) AS TableName,
    COL_NAME(fc.parent_object_id, c.parent_column_id) AS ColumnName,
    OBJECT_NAME (f.referenced_object_id) AS ReferenceTableName,
    COL_NAME(fc.referenced_object_id, fc.referenced_column_id) AS ReferenceColumnName
FROM sys.foreign_keys AS f
INNER JOIN sys.foreign_key_columns AS fc
ON f.OBJECT_ID = fc.constraint_object_id