Question

我刚从其他人那里继承了一个项目，我想知道是否有一种简单的方法可以识别数据库中的所有关系依赖关系，这样您就可以轻松地从生产中删除大量数据以创建开发人员复制但保持剩余帐户的关系不变。

Answer 1

这将以正确的顺序为您提供“模板SQL”。

但是你必须填写一些遗漏的where子句（不是无关紧要的）。

;
with    cteTableHierarchy 
          as ( /* Select all table without (selfreferencing) FK */
               select distinct
                        1 as LevelID
                      , OBJECT_SCHEMA_NAME(Parent.object_id) as TableOwner
                      , Parent.name as TableName
                      , Parent.object_id as TbObjID

               from     sys.objects Parent
               left join sys.foreign_key_columns RefKey
                        On RefKey.parent_object_id = Parent.object_id
                           and RefKey.parent_object_id <> RefKey.referenced_object_id
                           and RefKey.constraint_column_id = 1
               where    RefKey.parent_object_id is null
                        and Parent.type = 'U'
                        and Parent.name <> 'dtproperties'
               UNION ALL
               /* add tables that reference the anchor rows */
               SELECT   H.LevelID + 1
                      , OBJECT_SCHEMA_NAME(Parent.object_id) as TableOwner
                      , OBJECT_NAME(Parent.object_id) as TableName
                      , Parent.object_id as TbObjID
               from     sys.objects Parent
               inner join sys.foreign_key_columns RefKey
                        On RefKey.parent_object_id = Parent.object_id
                           and RefKey.parent_object_id <> RefKey.referenced_object_id
                           and RefKey.constraint_column_id = 1
               inner join cteTableHierarchy H
                        on H.TbObjID = RefKey.referenced_object_id 
               where    Parent.type = 'U'
                        and Parent.name <> 'dtproperties'
             )
    select distinct *    , TemplateSQL = 'Delete from [' + TableOwner + '].[' + TableName + '] Where .... '
    from    cteTableHierarchy
    order by LevelID desc -- descending order = order of row deletes
          , TableOwner
          , TableName ;

编辑........................

注释掉“Select *”并取消注释“Delete deleteAlias”以实际执行删除。关于这个小语法糖的好处（Select * vs“Delete deleteAlias”，你可以快速查看你将要删除的EXACT数据（通过select *）“删除deleteAlias”。

下面填充一个小的@Holder变量表。然后将反向走3个表.......删除数据。

注意，最后一个表（来自dbo。[Customers] deleteAlias）有一些冗余/不必要的代码，但我试图将这个概念展示为“简洁”。

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/* Example to Delete all Order-Details, Orders, Customers based on a known list of CustomerID's */

declare @CustomerIDHolder table ( CustomerID char(5) )
INSERT INTO @CustomerIDHolder ( CustomerID )
Select 'ALFKI' union all select '33333'


--Delete deleteAlias 
  Select * 
from dbo.[Order Details] deleteAlias
where exists 
    ( select null from dbo.[Orders] innerOrds join dbo.Customers innerCusts on innerOrds.CustomerID = innerCusts.CustomerID 
        where
        /* exists inner to outer relationshiop */
        innerOrds.OrderId = deleteAlias.OrderId
        and
        /* filter */
        exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )


--Delete deleteAlias 
  Select * 
from dbo.[Orders] deleteAlias
where exists 
    ( select null from dbo.Customers innerCusts
        where
        /* exists inner to outer relationshiop */
        innerCusts.CustomerID = deleteAlias.CustomerID
        and
        /* filter */
        exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )


--Delete deleteAlias 
  Select * 
from dbo.[Customers] deleteAlias
where exists 
    ( select null from dbo.Customers innerCusts
        where
        /* exists inner to outer relationshiop */
        innerCusts.CustomerID = deleteAlias.CustomerID
        and
        /* filter */
        exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )

这是一个“标记我要保留的东西，但删除其余的”示例........

/* Example to Delete all Order-Details, Orders, Customers based on a known list of CustomerID's */

declare @CustomerIDHolder table ( CustomerID char(5) )
INSERT INTO @CustomerIDHolder ( CustomerID )
Select CustomerID from dbo.Customers

/* Keep all the data except for 2 Customers.  Aka, The Customers who do NOT exist in the holder table will be deleted.... */
Delete deleteAliasHolder From @CustomerIDHolder deleteAliasHolder where exists ( Select CustID from (Select 'ALFKI' as CustID union all select '33333' as CustID ) as derived1 where derived1.CustID = deleteAliasHolder.CustomerID )

Select CustomerID as DataToKeepCustomerID from @CustomerIDHolder 

--Delete deleteAlias 
  Select * 
from dbo.[Order Details] deleteAlias
where exists 
    ( select null from dbo.[Orders] innerOrds join dbo.Customers innerCusts on innerOrds.CustomerID = innerCusts.CustomerID 
        where
        /* exists inner to outer relationshiop */
        innerOrds.OrderId = deleteAlias.OrderId
        and
        /* filter */
        not exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )


--Delete deleteAlias 
  Select * 
from dbo.[Orders] deleteAlias
where exists 
    ( select null from dbo.Customers innerCusts
        where
        /* exists inner to outer relationshiop */
        innerCusts.CustomerID = deleteAlias.CustomerID
        and
        /* filter */
        not exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )


--Delete deleteAlias 
  Select * 
from dbo.[Customers] deleteAlias
where exists 
    ( select null from dbo.Customers innerCusts
        where
        /* exists inner to outer relationshiop */
        innerCusts.CustomerID = deleteAlias.CustomerID
        and
        /* filter */
        not exists ( Select null from @CustomerIDHolder innerInnerHolder where innerInnerHolder.CustomerID = innerCusts.CustomerID )
  )

创建SQL Server数据库的开发版本的最佳方法是什么？

1 个答案: