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

我在2008年及以后一直在使用它。它类似于列出的其他一些解决方案,但字段名称是适当的大小写,以处理特定于大小写的(LatBin)排序。此外,您可以为它提供一个表名,并检索该表的信息。

-->>SPECIFY THE DESIRED DB
USE ???
GO

/*********************************************************************************************

    LIST OUT ALL PRIMARY AND FOREIGN KEY CONSTRAINTS IN A DB OR FOR A SPECIFIED TABLE

*********************************************************************************************/
DECLARE @tblName VARCHAR(255) 

/*******************/

    SET @tblName = NULL-->NULL will return all PK/FK constraints for every table in the database

/*******************/

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),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
       AND (   O1.name = @tblName 
            OR O2.name = @tblName
            OR @tblName IS null)
ORDER BY PKTABLE_NAME,FKTABLE_NAME

其他回答

以下的解决方案对我来说很有效:

--Eliminar las llaves foraneas
declare @query varchar(8000)
declare cursorRecorrerTabla cursor for

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


--3ro. abrir el cursor.
open cursorRecorrerTabla
fetch next from cursorRecorrerTabla
into @query
while @@fetch_status = 0
begin
--inicio cuerpo del cursor
    print @query
    exec(@query)
--fin cuerpo del cursor
fetch next from cursorRecorrerTabla
into @query
end
--cerrar cursor
close cursorRecorrerTabla
deallocate cursorRecorrerTabla

我知道这是一个很晚(非常晚)的回复,但我找到了这些简单的方法来找到所有的foreign_key_references。这是解决方案;

解决方案1:

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2:

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'

希望这对你有很大帮助。: -)

最简单的方法是使用sys。SQL中的foreign_keys_columns。这里的表包含了所有外键的对象ID,包括它们的引用列ID、引用表ID以及引用列和表。由于Id保持不变,因此对于Schema和表中的进一步修改,结果将是可靠的。

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'

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。

不知道为什么没有人建议,但我使用sp_fkeys查询给定表的外键:

EXEC sp_fkeys 'TableName'

你也可以指定模式:

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

在没有指定模式的情况下,文档声明如下:

如果没有指定pktable_owner,则默认表可见性规则 的基础DBMS应用程序。 在SQL Server中,如果当前用户拥有一个具有指定 Name,返回该表的列。如果pktable_owner不是 且当前用户不拥有具有指定属性的表 Pktable_name时,该过程查找具有指定 由数据库所有者拥有的Pktable_name。如果存在,那张桌子就是 返回列。