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

您还应该注意对其他对象的引用。

如果表被其他表高度引用,那么它也可能被其他对象(如视图、存储过程、函数等)高度引用。

我真的推荐GUI工具,如SSMS中的“查看依赖关系”对话框或免费工具,如ApexSQL Search,因为如果你只想用SQL来搜索其他对象的依赖关系,可能会出错。

如果SQL是唯一的选择,您可以尝试这样做。

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%'

其他回答

SQL Server中所有引用给定表的外键列表:

您可以通过以下查询获得引用表名和列名…

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'

下面的截图让你理解…

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。

我正在使用这个脚本来查找与外键相关的所有细节。 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

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

通过@Gishu所做的工作,我能够在SQL Server 2005中生成并使用以下SQL

SELECT t.name AS TableWithForeignKey, fk.constraint_column_id AS FK_PartNo, 
       c.name AS ForeignKeyColumn, o.name AS FK_Name 
  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
       INNER JOIN sys.objects AS o ON fk.constraint_object_id = o.object_id
  WHERE fk.referenced_object_id = (SELECT object_id FROM sys.tables 
                                        WHERE name = 'TableOthersForeignKeyInto')
  ORDER BY TableWithForeignKey, FK_PartNo;

在一个查询中显示表,列和外键名称。