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

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…

其他回答

以下是我认为在SQL Server 2016中处理这种情况的最佳实践。

你必须列出外键使用:

EXEC sp_fkeys 'TableName'

在这里你可以看到fk的全部信息。注意列FKTABLE_NAME, FKCOLUMN_NAME, FK_NAME, UPDATE_RULE, DELETE_RULE是你需要删除外键并在截断后再次实现它们的信息。

你可以组织一个脚本如下:

-- EXEC sp_fkeys 'TableName'

-- DROP CONSTRAINTS: I drop one, here drop every constraint you desire. 
BEGIN TRANSACTION
GO
ALTER TABLE dbo.TableName
    DROP CONSTRAINT IF EXISTS FK_TableName_OtherTable
GO
ALTER TABLE dbo.TableName SET (LOCK_ESCALATION = TABLE)
GO
COMMIT

-- TRUNCATE 
BEGIN TRANSACTION
TRUNCATE TABLE TableName
GO
COMMIT


-- RECREATE CONSTRAINTS: I recreate 1, here recreate every fk you desire
BEGIN TRANSACTION
GO
ALTER TABLE dbo.TableName SET (LOCK_ESCALATION = TABLE)
GO

ALTER TABLE dbo.TableName ADD CONSTRAINT
    FK_TableName_OtherTable FOREIGN KEY
    (
    Id_FK
    ) REFERENCES dbo.OtherTable
    (
    Id
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 
GO
COMMIT

** UPDATE_RULE和DELETE_RULE的值可以在sp_fkeys的文档中看到:

这个答案建立在sp_fkeys的基础上,但格式化类似于sp_fkeys,适用于多个列并列出它们的顺序。

SELECT fk_obj.name    AS FK_NAME,
       pk_schema.name AS PKTABLE_OWNER,
       pk_table.name  AS PKTABLE_NAME,
       pk_column.name AS PKCOLUMN_NAME,
       fk_schema.name AS FKTABLE_OWNER,
       fk_table.name  AS FKTABLE_NAME,
       fk_column.name AS FKCOLUMN_NAME,
       ROW_NUMBER() over (
           PARTITION BY fk_obj.name, fk_schema.name
           ORDER BY fkc.constraint_column_id
           )          AS KEY_SEQ
FROM sys.foreign_key_columns fkc
         INNER JOIN sys.objects fk_obj
                    ON fk_obj.object_id = fkc.constraint_object_id
         INNER JOIN sys.tables fk_table
                    ON fk_table.object_id = fkc.parent_object_id
         INNER JOIN sys.schemas fk_schema
                    ON fk_table.schema_id = fk_schema.schema_id
         INNER JOIN sys.columns fk_column
                    ON fk_column.column_id = parent_column_id
                        AND fk_column.object_id = fk_table.object_id
         INNER JOIN sys.tables pk_table
                    ON pk_table.object_id = fkc.referenced_object_id
         INNER JOIN sys.schemas pk_schema
                    ON pk_table.schema_id = pk_schema.schema_id
         INNER JOIN sys.columns pk_column
                    ON pk_column.column_id = fkc.referenced_column_id
                        AND pk_column.object_id = pk_table.object_id;

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…

试试这个:

sp_help 'TableName'

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