MSSQL,通过T-SQL脚本查询表的所有外键

　　 当我们要对两个数据库的相关数据进行完全同步的时候，我们首先是先删除数据，然后再添加数据，这样保证所有数据的一致性，

那么假设现在我们需要从源数据库中的表A同步到目标数据库中的表A，脚本如下

1.delete  targetDBName.dbo.TBA   

2.insert into targetDBName.dbo.TBA select * from sourceDBName.dbo.TBA  （动态字段可以查询syscolumns表来实现）

那么在执行第一句脚本的时候，就有可能报错，因为TBA有可能存在外键关联。

　　在这种的情况下，

　　　　删除操作：先删子表在删主表

　　　　添加操作：先添主表在添子表

   因此我们需要对TBA的所有外键进行排查，脚本如下：

--查询外键约束
select FK_Name as [外键名],Parent_Tab_Name as [外键表],
    [外键列]=stuff((select '，'+[Parent_Col_Name] from (
        select    FK.name as FK_Name,Parent_Tab.Name as Parent_Tab_Name,Parent_Col.Name as Parent_Col_Name,
                Referenced_Tab.Name as Referenced_Tab_Name,Referenced_Col.Name as Referenced_Col_Name
        from sys.foreign_keys FK
        inner join sys.foreign_key_columns Col on FK.Object_ID = Col.constraint_object_id
        inner join sys.objects Parent_Tab ON  Col.parent_object_id = Parent_Tab.Object_ID and Parent_Tab.TYPE = 'U'
        inner join sys.columns Parent_Col on Parent_Tab.Object_ID = Parent_Col.object_id 
                                            and  Col.parent_column_id = Parent_Col.column_id
        inner join sys.objects Referenced_Tab ON  Col.referenced_object_id = Referenced_Tab.Object_ID 
 　　　　　　　　and Referenced_Tab.TYPE = 'U'
        inner join sys.columns Referenced_Col on Referenced_Tab.Object_ID = Referenced_Col.object_id 
                                            and  Col.referenced_column_id = Referenced_Col.column_id
    )t where FK_Name=tb.FK_Name  and Parent_Tab_Name = tb.Parent_Tab_Name 
　　　　and Referenced_Tab_Name = tb.Referenced_Tab_Name   for xml path('')), 1, 1, ''),
    Referenced_Tab_Name as  [主键表],
    [主键列]=stuff((select '，'+[Referenced_Col_Name] from (
        select    FK.name as FK_Name,Parent_Tab.Name as Parent_Tab_Name,Parent_Col.Name as Parent_Col_Name,
                Referenced_Tab.Name as Referenced_Tab_Name,Referenced_Col.Name as Referenced_Col_Name
        from sys.foreign_keys FK
        inner join sys.foreign_key_columns Col on FK.Object_ID = Col.constraint_object_id
        inner join sys.objects Parent_Tab ON  Col.parent_object_id = Parent_Tab.Object_ID and Parent_Tab.TYPE = 'U'
        inner join sys.columns Parent_Col on Parent_Tab.Object_ID = Parent_Col.object_id 
                                            and  Col.parent_column_id = Parent_Col.column_id
        inner join sys.objects Referenced_Tab ON  Col.referenced_object_id = Referenced_Tab.Object_ID 
　　　　　　　　and Referenced_Tab.TYPE = 'U'
        inner join sys.columns Referenced_Col on Referenced_Tab.Object_ID = Referenced_Col.object_id 
                                            and  Col.referenced_column_id = Referenced_Col.column_id
    )t where FK_Name=tb.FK_Name  and Parent_Tab_Name = tb.Parent_Tab_Name 
　　　　and Referenced_Tab_Name = tb.Referenced_Tab_Name   for xml path('')), 1, 1, '')
    --as [外键列]
from (
    select    FK.name as FK_Name,Parent_Tab.Name as Parent_Tab_Name,Parent_Col.Name as Parent_Col_Name,
            Referenced_Tab.Name as Referenced_Tab_Name,Referenced_Col.Name as Referenced_Col_Name
    from sys.foreign_keys FK
    inner join sys.foreign_key_columns Col on FK.Object_ID = Col.constraint_object_id
    inner join sys.objects Parent_Tab ON  Col.parent_object_id = Parent_Tab.Object_ID and Parent_Tab.TYPE = 'U'
    inner join sys.columns Parent_Col on Parent_Tab.Object_ID = Parent_Col.object_id 
                                        and  Col.parent_column_id = Parent_Col.column_id
    inner join sys.objects Referenced_Tab ON  Col.referenced_object_id = Referenced_Tab.Object_ID 
　　　　　　and Referenced_Tab.TYPE = 'U'
    inner join sys.columns Referenced_Col on Referenced_Tab.Object_ID = Referenced_Col.object_id 
                                        and  Col.referenced_column_id = Referenced_Col.column_id
)tb
--WHERE tb.Parent_Tab_Name='PB_UserRole' OR tb.Referenced_Tab_Name='PB_UserRole'
group by FK_Name,Parent_Tab_Name,Referenced_Tab_Name