我需要在SQL Server数据库中删除一个高度引用的表。我如何才能得到所有外键约束的列表,我将需要删除以便删除表?

(SQL比在管理工作室的GUI中点击更可取)


当前回答

也试一试。

EXEC sp_fkeys 'tableName', 'schemaName'

使用sp_fkeys,不仅可以通过pk表名和模式过滤结果,还可以通过fk表名和模式过滤结果。链接

其他回答

上面有一些不错的答案。但我更喜欢一个问题就能得到答案。 这段代码来自sys. .Sp_helpconstraint (sys proc)

这是微软查找是否有与tbl关联的外键的方法。

--setup variables. Just change 'Customer' to tbl you want
declare @objid int,
    @objname nvarchar(776)
select @objname = 'Customer'    
select @objid = object_id(@objname)

if exists (select * from sys.foreign_keys where referenced_object_id = @objid)
    select 'Table is referenced by foreign key' =
        db_name() + '.'
        + rtrim(schema_name(ObjectProperty(parent_object_id,'schemaid')))
        + '.' + object_name(parent_object_id)
        + ': ' + object_name(object_id)
    from sys.foreign_keys 
    where referenced_object_id = @objid 
    order by 1

答案看起来像这样:test_db_name.dbo。账户:FK_Account_Customer

你可以通过以下查询找到:

 SELECT OBJECT_NAME (FK.referenced_object_id) 'Referenced Table', 
      OBJECT_NAME(FK.parent_object_id) 'Referring Table', FK.name 'Foreign Key', 
      COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) 'Referenced Column',
      COL_NAME(FK.parent_object_id,FKC.parent_column_id) 'Referring Column'
     FROM sys.foreign_keys AS FK
             INNER JOIN sys.foreign_key_columns AS FKC 
                 ON FKC.constraint_object_id = FK.OBJECT_ID
     WHERE OBJECT_NAME (FK.referenced_object_id) = 'YourTableName'
     AND COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) = 'YourColumnName'
     order by  OBJECT_NAME(FK.parent_object_id)
SELECT
  object_name(parent_object_id),
  object_name(referenced_object_id),
  name 
FROM sys.foreign_keys
WHERE parent_object_id = object_id('Table Name')

最初的问题要求将所有外键的列表放入一个高度引用的表中,以便可以删除表。

这个小查询返回将所有外键放入特定表所需的“drop foreign key”命令:

SELECT 
   'ALTER TABLE ['+sch.name+'].['+referencingTable.Name+'] DROP CONSTRAINT ['+foreignKey.name+']' '[DropCommand]'
FROM sys.foreign_key_columns fk
    JOIN sys.tables referencingTable ON fk.parent_object_id = referencingTable.object_id
    JOIN sys.schemas sch ON referencingTable.schema_id = sch.schema_id
    JOIN sys.objects foreignKey ON foreignKey.object_id = fk.constraint_object_id
    JOIN sys.tables referencedTable ON fk.referenced_object_id = referencedTable.object_id
WHERE referencedTable.name = 'MyTableName'

示例输出:

[DropCommand]
ALTER TABLE [dbo].[OtherTable1] DROP CONSTRAINT [FK_OtherTable1_MyTable]
ALTER TABLE [dbo].[OtherTable2] DROP CONSTRAINT [FK_OtherTable2_MyTable]

省略where -子句以获取当前数据库中所有外键的删除命令。

我将使用SQL Server Management Studio中的数据库图表功能,但既然你排除了它-这在SQL Server 2008中为我工作(没有2005)。

获取引用表和列名的列表…

select 
    t.name as TableWithForeignKey, 
    fk.constraint_column_id as FK_PartNo, c.
    name as ForeignKeyColumn 
from 
    sys.foreign_key_columns as fk
inner join 
    sys.tables as t on fk.parent_object_id = t.object_id
inner join 
    sys.columns as c on fk.parent_object_id = c.object_id and fk.parent_column_id = c.column_id
where 
    fk.referenced_object_id = (select object_id 
                               from sys.tables 
                               where name = 'TableOthersForeignKeyInto')
order by 
    TableWithForeignKey, FK_PartNo

获取外键约束的名称

select distinct name from sys.objects where object_id in 
(   select fk.constraint_object_id from sys.foreign_key_columns as fk
    where fk.referenced_object_id = 
        (select object_id from sys.tables where name = 'TableOthersForeignKeyInto')
)