SQL Server Team-based Development - Red Gate Software

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Chapter 8: Exploring your Database Schema
SELECT fk.name
FROM sys.foreign_Key_columns fkc
INNER JOIN sys.foreign_keys fk ON fkc.constraint_object_id = fk.object_id
GROUP BY fk.name
HAVING COUNT(*) = 1
Listing 8-20: Finding composite foreign keys.
This complicates the SQL that you'd use to generate these relationships, as you can see
from Listing 8-21, which shows the SQL to get all the relationships for a particular table in
the database, in this case, the HumanResources.Employee table.
SELECT SUBSTRING(( SELECT ' AND ' + Object_Schema_name(fk.Parent_object_ID)
+ '.' + OBJECT_NAME(fk.Parent_object_ID) + '.'
+ cr.name + ' = '
+ Object_Schema_name(fkc.referenced_object_id)
+ '.' + OBJECT_NAME(fkc.referenced_object_id)
+ '.' + c.NAME
FROM sys.foreign_Key_columns fkc
INNER JOIN sys.columns c
ON fkc.referenced_column_id = c.column_id
AND fkc.referenced_object_id = c.object_id
INNER JOIN sys.columns cr
ON fkc.parent_column_id = cr.column_id
AND fkc.parent_object_id = cr.object_id
WHERE fkc.constraint_object_id = fk.OBJECT_ID
FOR
XML PATH('')
), 6, 2000) + ' – – ' + fk.name
FROM sys.foreign_keys fk
WHERE fk.referenced_object_ID = OBJECT_ID('HumanResources.Employee')
OR fk.parent_object_id = OBJECT_ID('HumanResources.Employee')
Listing 8-21: A query to find all the FK relationships for a given table.