如何列出引用SQL Server中给定表的所有外键？

Question

我需要删除SQL Server数据库中高度引用的表.如何获取我需要删除的所有外键约束的列表以便删除表？

(在管理工作室的GUI中,SQL答案比点击更好.)

Answer 1

不知道为什么没有人建议,但我sp_fkeys用来查询给定表的外键:

EXEC sp_fkeys 'TableName'

您还可以指定架构:

EXEC sp_fkeys @pktable_name = 'TableName', @pktable_owner = 'dbo'

如果不指定架构,文档将声明以下内容:

如果未指定pktable_owner,则应用基础DBMS的默认表可见性规则.

在SQL Server中,如果当前用户拥有具有指定名称的表,则返回该表的列.如果未指定pktable_owner且当前用户不拥有具有指定pktable_name的表,则该过程将查找具有数据库所有者拥有的指定pktable_name的表.如果存在,则返回该表的列.

Answer 2

我在SQL Server Management Studio中使用了数据库图表功能,但是由于你排除了这一点 - 这在SQL Server 2008中对我有用(没有2005).

获取引用表和列名列表...

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')
)

Answer 3

这给你:

• FK本身
• FK所属的架构
• " 引用表 "或具有FK的表
• " 引用列 "或引用表中指向FK的列
• " 引用表 "或具有FK指向的键列的表
• " 引用列 "或FK指向的键的列

代码如下:

SELECT  obj.name AS FK_NAME,
    sch.name AS [schema_name],
    tab1.name AS [table],
    col1.name AS [column],
    tab2.name AS [referenced_table],
    col2.name AS [referenced_column]
FROM sys.foreign_key_columns fkc
INNER JOIN sys.objects obj
    ON obj.object_id = fkc.constraint_object_id
INNER JOIN sys.tables tab1
    ON tab1.object_id = fkc.parent_object_id
INNER JOIN sys.schemas sch
    ON tab1.schema_id = sch.schema_id
INNER JOIN sys.columns col1
    ON col1.column_id = parent_column_id AND col1.object_id = tab1.object_id
INNER JOIN sys.tables tab2
    ON tab2.object_id = fkc.referenced_object_id
INNER JOIN sys.columns col2
    ON col2.column_id = referenced_column_id AND col2.object_id = tab2.object_id

Answer 4

试试这个 :

sp_help 'TableName'

Answer 5

您还应该注意对其他对象的引用.

如果该表被其他表高度引用,那么它可能也被其他对象高度引用,例如视图,存储过程,函数等.

我真的建议使用GUI工具,例如SSMS中的"查看依赖关系"对话框或像ApexSQL这样的免费工具搜索,因为如果只想用SQL来搜索其他对象中的依赖关系,则可能容易出错.

如果SQL是唯一的选择,你可以尝试这样做.

select O.name as [Object_Name], C.text as [Object_Definition]
from sys.syscomments C
inner join sys.all_objects O ON C.id = O.object_id
where C.text like '%table_name%'

Answer 6

原始问题要求将所有外键的列表放入高度引用的表中,以便可以删除该表.

这个小查询返回将所有外键放入特定表所需的所有"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drop命令.

Answer 7

这是我将使用的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

SQL不是特别清楚,所以让我们看一个例子.

所以,假设我想把Employees表放在微软心爱的Northwind数据库中,但是SQL Server告诉我一个或多个外键阻止我这样做.

上面的SQL命令会返回这些结果......

它告诉我有3个外键引用该Employees表.换句话说,在第一次删除这三个外键之前,我不允许删除(删除)此表.

在结果中,第一行是如何在结果中显示以下外键约束.

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用来删除其中一个外键的SQL命令,例如:

ALTER TABLE [Employees] DROP CONSTRAINT [FK_Employees_Employees]

...并且右侧列显示了用于创建它的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,您可以获得删除相关外键所需的一切,以便删除表,然后再重新创建.

唷.希望这可以帮助.

Answer 8

SELECT PKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
       PKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O1.SCHEMA_ID)),
       PKTABLE_NAME = CONVERT(SYSNAME,O1.NAME),
       PKCOLUMN_NAME = CONVERT(SYSNAME,C1.NAME),
       FKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
       FKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O2.SCHEMA_ID)),
       FKTABLE_NAME = CONVERT(SYSNAME,O2.NAME),
       FKCOLUMN_NAME = CONVERT(SYSNAME,C2.NAME),
       -- Force the column to be non-nullable (see SQL BU 325751)
       --KEY_SEQ             = isnull(convert(smallint,k.constraint_column_id), sysconv(smallint,0)),
       UPDATE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsUpdateCascade') 
                                        WHEN 1 THEN 0
                                        ELSE 1
                                      END),
       DELETE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsDeleteCascade') 
                                        WHEN 1 THEN 0
                                        ELSE 1
                                      END),
       FK_NAME = CONVERT(SYSNAME,OBJECT_NAME(F.OBJECT_ID)),
       PK_NAME = CONVERT(SYSNAME,I.NAME),
       DEFERRABILITY = CONVERT(SMALLINT,7)   -- SQL_NOT_DEFERRABLE
FROM   SYS.ALL_OBJECTS O1,
       SYS.ALL_OBJECTS O2,
       SYS.ALL_COLUMNS C1,
       SYS.ALL_COLUMNS C2,
       SYS.FOREIGN_KEYS F
       INNER JOIN SYS.FOREIGN_KEY_COLUMNS K
         ON (K.CONSTRAINT_OBJECT_ID = F.OBJECT_ID)
       INNER JOIN SYS.INDEXES I
         ON (F.REFERENCED_OBJECT_ID = I.OBJECT_ID
             AND F.KEY_INDEX_ID = I.INDEX_ID)
WHERE  O1.OBJECT_ID = F.REFERENCED_OBJECT_ID
       AND O2.OBJECT_ID = F.PARENT_OBJECT_ID
       AND C1.OBJECT_ID = F.REFERENCED_OBJECT_ID
       AND C2.OBJECT_ID = F.PARENT_OBJECT_ID
       AND C1.COLUMN_ID = K.REFERENCED_COLUMN_ID
       AND C2.COLUMN_ID = K.PARENT_COLUMN_ID

Answer 9

最简单的方法是在SQL中使用sys.foreign_keys_columns.这里的表包含所有外键的Object ID,以及它们的Referenced列ID引用表ID以及引用列和表.由于Id的值保持不变,因此结果对于Schema和表格的进一步修改是可靠的.

查询:

SELECT    
OBJECT_NAME(fkeys.constraint_object_id) foreign_key_name
,OBJECT_NAME(fkeys.parent_object_id) referencing_table_name
,COL_NAME(fkeys.parent_object_id, fkeys.parent_column_id) referencing_column_name
,OBJECT_SCHEMA_NAME(fkeys.parent_object_id) referencing_schema_name
,OBJECT_NAME (fkeys.referenced_object_id) referenced_table_name
,COL_NAME(fkeys.referenced_object_id, fkeys.referenced_column_id) 
referenced_column_name
,OBJECT_SCHEMA_NAME(fkeys.referenced_object_id) referenced_schema_name
FROM sys.foreign_key_columns AS fkeys

我们还可以使用'where'添加过滤器

WHERE OBJECT_NAME(fkeys.parent_object_id) = 'table_name' AND 
OBJECT_SCHEMA_NAME(fkeys.parent_object_id) = 'schema_name'

Answer 10

SELECT
  object_name(parent_object_id),
  object_name(referenced_object_id),
  name 
FROM sys.foreign_keys
WHERE parent_object_id = object_id('Table Name')

Answer 11

我正在使用此脚本查找与外键相关的所有详细信息.我正在使用INFORMATION.SCHEMA.下面是一个SQL脚本:

SELECT 
    ccu.table_name AS SourceTable
    ,ccu.constraint_name AS SourceConstraint
    ,ccu.column_name AS SourceColumn
    ,kcu.table_name AS TargetTable
    ,kcu.column_name AS TargetColumn
FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu
    INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc
        ON ccu.CONSTRAINT_NAME = rc.CONSTRAINT_NAME 
    INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE kcu 
        ON kcu.CONSTRAINT_NAME = rc.UNIQUE_CONSTRAINT_NAME  
ORDER BY ccu.table_name

Answer 12

第一

EXEC sp_fkeys 'Table', 'Schema'

然后使用NimbleText来播放您的结果

Answer 13

引用 SQL Server 中给定表的所有外键的列表：

您可以通过以下查询获取引用表名和列名...

SELECT 
   OBJECT_NAME(f.parent_object_id) TableName,
   COL_NAME(fc.parent_object_id,fc.parent_column_id) ColName
FROM 
   sys.foreign_keys AS f
INNER JOIN 
   sys.foreign_key_columns AS fc 
      ON f.OBJECT_ID = fc.constraint_object_id
INNER JOIN 
   sys.tables t 
      ON t.OBJECT_ID = fc.referenced_object_id
WHERE 
   OBJECT_NAME (f.referenced_object_id) = 'TableName'

以及以下屏幕截图供您理解...

Answer 14

我知道这是一个迟到（非常晚）的答复，但我发现这些简单的方法可以找到所有foreign_key_references. 这是解决方案；

解决方案01：

EXEC SP_FKEYS 'MyTableName';   // It'll show you the all the information(in multiple tables) regarding to the TableName with all ForeignKey_References.

解决方案02：

EXEC SP_HELP 'MyTableName';   // It'll show all ForeignKey references in a single table.

解决方案03：

// It'll show you the Column_Name with Referenced_Table_Name

SELECT 
   COL_NAME(fc.parent_object_id,fc.parent_column_id) Column_Name,
   OBJECT_NAME(f.parent_object_id) Table_Name
FROM 
   sys.foreign_keys AS f
INNER JOIN 
   sys.foreign_key_columns AS fc 
      ON f.OBJECT_ID = fc.constraint_object_id
INNER JOIN 
   sys.tables t 
      ON t.OBJECT_ID = fc.referenced_object_id
WHERE 
   OBJECT_NAME (f.referenced_object_id) = 'MyTableName'

希望这会对您有很大帮助。;-)

Answer 15

 SELECT OBJECT_NAME(fk.parent_object_id) as ReferencingTable, 
        OBJECT_NAME(fk.constraint_object_id) as [FKContraint]
  FROM sys.foreign_key_columns as fk
 WHERE fk.referenced_object_id = OBJECT_ID('ReferencedTable', 'U')

如果是外键约束，这仅显示关系。我的数据库显然早于 FK 约束。一些表使用触发器来强制执行参照完整性，有时只有一个类似命名的列来指示关系（并且根本没有参照完整性）。

幸运的是，我们确实有一个一致的命名场景，所以我能够找到这样的引用表和视图：

SELECT OBJECT_NAME(object_id) from sys.columns where name like 'client_id'

我使用此选择作为生成脚本的基础，该脚本执行我需要在相关表上执行的操作。

Answer 16

上面有一些好的答案.但我更喜欢用一个查询得到答案.这段代码取自sys.sp_helpconstraint(sys proc)

如果有与tbl关联的外键,那就是Microsoft查找的方式.

--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

答案如下所示:test_db_name.dbo.Account:FK_Account_Customer

Answer 17

SELECT
OBJECT_NAME(parent_object_id) 'Parent table',
c.NAME 'Parent column name',
OBJECT_NAME(referenced_object_id) 'Referenced table',
cref.NAME 'Referenced column name'
FROM 
sys.foreign_key_columns fkc 
INNER JOIN 
sys.columns c 
   ON fkc.parent_column_id = c.column_id 
      AND fkc.parent_object_id = c.object_id
INNER JOIN 
sys.columns cref 
   ON fkc.referenced_column_id = cref.column_id 
      AND fkc.referenced_object_id = cref.object_id  where   OBJECT_NAME(parent_object_id) = 'tablename'

如果要获取所有表的外键关系,则排除where子句,否则写入您的表名而不是tablename

Answer 18

@BankZ 的最佳答案

sp_help 'TableName'   

另外对于不同的模式

sp_help 'schemaName.TableName'