我如何能列出所有外键引用SQL Server中给定的表?

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

下面是我将使用的SQL代码。

SELECT 
   f.name AS 'Name of Foreign Key',
   OBJECT_NAME(f.parent_object_id) AS 'Table name',
   COL_NAME(fc.parent_object_id,fc.parent_column_id) AS 'Fieldname',
   OBJECT_NAME(t.object_id) AS 'References Table name',
   COL_NAME(t.object_id,fc.referenced_column_id) AS 'References fieldname',

   'ALTER TABLE [' + OBJECT_NAME(f.parent_object_id) + ']  DROP CONSTRAINT [' + f.name + ']' AS 'Delete foreign key',

   'ALTER TABLE [' + OBJECT_NAME(f.parent_object_id) + ']  WITH NOCHECK ADD CONSTRAINT [' + 
        f.name + '] FOREIGN KEY([' + COL_NAME(fc.parent_object_id,fc.parent_column_id) + ']) REFERENCES ' + 
        '[' + OBJECT_NAME(t.object_id) + '] ([' +
        COL_NAME(t.object_id,fc.referenced_column_id) + '])' AS 'Create foreign key'
    -- , delete_referential_action_desc AS 'UsesCascadeDelete'
FROM sys.foreign_keys AS f,
     sys.foreign_key_columns AS fc,
     sys.tables t 
WHERE f.OBJECT_ID = fc.constraint_object_id
AND t.OBJECT_ID = fc.referenced_object_id
AND OBJECT_NAME(t.object_id) = 'Employees'      --  Just show the FKs which reference a particular table
ORDER BY 2

这不是特别清晰的SQL，所以让我们看一个例子。

所以，假设我想删除Microsoft心爱的Northwind数据库中的Employees表，但是SQL Server告诉我一个或多个外键阻止我这样做。

上面的SQL命令将返回这些结果…

它显示有3个外键引用雇员表。换句话说，除非先删除这三个外键，否则不允许删除(删除)这个表。

在结果中，第一行是以下外键约束在结果中的显示方式。

ALTER TABLE [dbo].[Employees]  WITH NOCHECK 
ADD CONSTRAINT [FK_Employees_Employees] FOREIGN KEY([ReportsTo])
REFERENCES [dbo].[Employees] ([EmployeeID])

倒数第二列显示了我需要使用的SQL命令来删除这些外键之一，例如:

ALTER TABLE [Employees] DROP CONSTRAINT [FK_Employees_Employees]

.．.右边一列显示了创建它的SQL…

ALTER TABLE [Employees] WITH NOCHECK 
ADD CONSTRAINT [FK_Employees_Employees] 
FOREIGN KEY([ReportsTo]) REFERENCES [Employees] ([EmployeeID])

使用所有这些命令，您就拥有了删除相关外键所需的一切，从而可以删除表，然后再重新创建它们。

唷。希望这能有所帮助。

2017-05-03 09:35:51

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

2012-04-25 14:28:16

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')
)

2009-01-27 12:43:35

@BankZ的最好回答

sp_help 'TableName'

另外，对于不同的模式

sp_help 'schemaName.TableName'

2019-11-22 20:56:14