Sql server 如何在一个表中的不同字段之间获取FKs？

如果一个字段引用到同一表中的另一个字段，如何从DB中获取所有约束

这种类型的引用会严重影响性能，因此我希望在数据库中找到所有这些引用并对它们进行分析

表结构的示例：

CREATE TABLE MyTable(id uniqueidentifier NOT NULL PRIMARY KEY, ReferentID uniqueidentifier)

ALTER TABLE [dbo].MyTable  WITH CHECK ADD  CONSTRAINT [TEST_FK] FOREIGN KEY([ReferentID])
REFERENCES [dbo].MyTable ([Id])
GO

ALTER TABLE [dbo].MyTable CHECK CONSTRAINT [TEST_FK]
GO

---

您可以从此

过程中获取所有
外键

EXEC sp_fkeys 'MyTable';

或者您可以使用：

select * from sysobjects where xtype='F';

从应答中的查询开始，您可以添加一个过滤器，以仅获取引用同一表的FK

生成的查询应如下所示：

SELECT  
     KCU1.CONSTRAINT_NAME AS FK_CONSTRAINT_NAME 
    ,KCU1.TABLE_NAME AS FK_TABLE_NAME --
    ,KCU1.COLUMN_NAME AS FK_COLUMN_NAME 
    ,KCU1.ORDINAL_POSITION AS FK_ORDINAL_POSITION 
    ,KCU2.CONSTRAINT_NAME AS REFERENCED_CONSTRAINT_NAME 
    ,KCU2.TABLE_NAME AS REFERENCED_TABLE_NAME --
    ,KCU2.COLUMN_NAME AS REFERENCED_COLUMN_NAME 
    ,KCU2.ORDINAL_POSITION AS REFERENCED_ORDINAL_POSITION 
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC 

INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU1 
    ON KCU1.CONSTRAINT_CATALOG = RC.CONSTRAINT_CATALOG  
    AND KCU1.CONSTRAINT_SCHEMA = RC.CONSTRAINT_SCHEMA 
    AND KCU1.CONSTRAINT_NAME = RC.CONSTRAINT_NAME 

INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU2 
    ON KCU2.CONSTRAINT_CATALOG = RC.UNIQUE_CONSTRAINT_CATALOG  
    AND KCU2.CONSTRAINT_SCHEMA = RC.UNIQUE_CONSTRAINT_SCHEMA 
    AND KCU2.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME 
    AND KCU2.ORDINAL_POSITION = KCU1.ORDINAL_POSITION 

WHERE   KCU1.TABLE_NAME=KCU2.TABLE_NAME