如何使用Sql Server 2008查找表的外鍵？

Question

我可以用這個查詢得到一個表的列在SQL Server：

select * from information_schema.columns where table_name = 'MyTable' 

但如何找到與該表相關聯的外鍵列？

Answer 1

它在裏面information_schema.table_constraints。

編輯：

等待，我認爲information_schema.key_column_usage更好：

select * from information_schema.key_column_usage where table_name = '...' 

，然後如果你需要確保它確實是一個外鍵，使用你得到了約束名稱查詢TABLE_CONSTRAINTS從上面：

select * from information_schema.table_constraints where constraint_name = '...' 

Answer 2

這將找到給定表上的所有FK約束。只需將'table_name'設置爲您的表格名稱即可。查詢如下：

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

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=@TABLENAME