249.标的外键约束

--表的外键约束

SELECT 外键表ID=b.fkeyid
	,外键表名称=object_name(b.fkeyid)
	,外键列ID=b.fkey
	,外键列名=(SELECT name FROM syscolumns WHERE colid=b.fkey AND id=b.fkeyid)
	,主键表ID=b.rkeyid
	,主键表名=object_name(b.rkeyid)
	,主键列ID=b.rkey
	,主键列名=(SELECT name FROM syscolumns WHERE colid=b.rkey AND id=b.rkeyid)
	,级联更新=ObjectProperty(a.id,'CnstIsUpdateCascade')
	,级联删除=ObjectProperty(a.id,'CnstIsDeleteCascade')
FROM sysobjects a
	join sysforeignkeys b on a.id=b.constid
	join sysobjects c on a.parent_obj=c.id
where a.xtype='f' AND c.xtype='U'


--查询一个表的所有外键:

SELECT 主键列ID=b.rkey
	,主键列名=(SELECT name FROM syscolumns WHERE colid=b.rkey AND id=b.rkeyid)
	,外键表ID=b.fkeyid
	,外键表名称=object_name(b.fkeyid)
	,外键列ID=b.fkey
	,外键列名=(SELECT name FROM syscolumns WHERE colid=b.fkey AND id=b.fkeyid)
	,级联更新=ObjectProperty(a.id,'CnstIsUpdateCascade')
	,级联删除=ObjectProperty(a.id,'CnstIsDeleteCascade')
FROM sysobjects a
	join sysforeignkeys b on a.id=b.constid
	join sysobjects c on a.parent_obj=c.id
where a.xtype='f' AND c.xtype='U'
	and object_name(b.rkeyid)='titles'