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社区首页 >问答首页 >SQLServer:如何按表名的外键依赖项排序

SQLServer:如何按表名的外键依赖项排序
EN

Stack Overflow用户
提问于 2008-12-09 09:03:38
回答 4查看 13.8K关注 0票数 21

下面的SQL根据表之间的关系来分隔表。问题出在3000系列下排序的表。作为外键的一部分并且使用外键的表。谁有一些聪明的递归CTE或存储过程来做必要的排序?连接到数据库的程序不被视为解决方案。

编辑:我在“答案”中张贴了答案,基于第一个解决方案免费“正确答案”,以便任何人转发我自己的“正确”答案!

WITH 
 AllTables(TableName) AS
 (
 SELECT OBJECT_SCHEMA_NAME(so.id) +'.'+ OBJECT_NAME(so.id) 
 FROM dbo.sysobjects so 
 INNER JOIN sys.all_columns ac ON 
  so.ID = ac.object_id
 WHERE
  so.type = 'U'
 AND
  ac.is_rowguidcol = 1
 ),

  Relationships(ReferenceTableName, ReferenceColumnName, TableName, ColumnName)  AS
  (
  SELECT  
    OBJECT_SCHEMA_NAME (fkey.referenced_object_id) + '.' +  
    OBJECT_NAME (fkey.referenced_object_id) AS ReferenceTableName 
    ,COL_NAME(fcol.referenced_object_id, 
              fcol.referenced_column_id) AS ReferenceColumnName 
    ,OBJECT_SCHEMA_NAME (fkey.parent_object_id) + '.' +  
    OBJECT_NAME(fkey.parent_object_id) AS TableName 
    ,COL_NAME(fcol.parent_object_id, fcol.parent_column_id) AS ColumnName 
  FROM sys.foreign_keys AS fkey 
    INNER JOIN sys.foreign_key_columns AS fcol ON 
               fkey.OBJECT_ID = fcol.constraint_object_id 
  ),

 NotReferencedOrReferencing(TableName) AS
 (
 SELECT TableName FROM AllTables
 EXCEPT
 SELECT TableName FROM Relationships
 EXCEPT
 SELECT ReferenceTableName FROM Relationships
 ),

 OnlyReferenced(Tablename) AS
 (
 SELECT ReferenceTableName FROM Relationships
 EXCEPT
 SELECT TableName FROM Relationships
 ),
-- These need to be sorted based on theire internal relationships
 ReferencedAndReferencing(TableName, ReferenceTableName) AS
 (
 SELECT r1.Tablename, r2.ReferenceTableName FROM Relationships r1 
 INNER JOIN Relationships r2
 ON r1.TableName = r2.ReferenceTableName   
 ),

 OnlyReferencing(TableName) AS
 (
 SELECT Tablename FROM Relationships
 EXCEPT
 SELECT ReferenceTablename FROM Relationships
 )
SELECT TableName, 1000 AS Sorting FROM NotReferencedOrReferencing
UNION
SELECT TableName, 2000 AS Sorting FROM OnlyReferenced 
UNION
SELECT TableName, 3000 AS Sorting FROM ReferencedAndReferencing
UNION
SELECT TableName, 4000 AS Sorting FROM OnlyReferencing
ORDER BY Sorting
EN

回答 4

Stack Overflow用户

回答已采纳

发布于 2008-12-11 09:55:38

感谢您的工作解决方案NXC。您让我走上了使用递归CTE解决问题的正确道路。

WITH 
  TablesCTE(TableName, TableID, Ordinal) AS
  (
  SELECT 
    OBJECT_SCHEMA_NAME(so.id) +'.'+ OBJECT_NAME(so.id) AS TableName,
    so.id AS TableID,
    0 AS Ordinal
  FROM dbo.sysobjects so INNER JOIN sys.all_columns ac ON so.ID = ac.object_id
  WHERE
    so.type = 'U'
  AND
    ac.is_rowguidcol = 1
  UNION ALL
  SELECT 
    OBJECT_SCHEMA_NAME(so.id) +'.'+ OBJECT_NAME(so.id) AS TableName,
    so.id AS TableID,
    tt.Ordinal + 1 AS Ordinal
  FROM 
    dbo.sysobjects so 
    INNER JOIN sys.all_columns ac ON so.ID = ac.object_id
    INNER JOIN sys.foreign_keys f 
      ON (f.parent_object_id = so.id AND f.parent_object_id != f.referenced_object_id)
    INNER JOIN TablesCTE tt ON f.referenced_object_id = tt.TableID
  WHERE
    so.type = 'U'
  AND
    ac.is_rowguidcol = 1
)  
SELECT DISTINCT 
  t.Ordinal,
  t.TableName
  FROM TablesCTE t
  INNER JOIN 
    (
    SELECT 
      TableName as TableName,
      Max (Ordinal) as Ordinal
    FROM TablesCTE
    GROUP BY TableName
    ) tt ON (t.TableName = tt.TableName  AND t.Ordinal = tt.Ordinal)
ORDER BY t.Ordinal, t.TableName

对于thoose来说,想知道这有什么用:我将使用它安全地清空数据库,而不会违反任何外键关系。(通过按降序截断)我还可以通过按升序填充表来使用来自另一个数据库的数据安全地填充表。

票数 9
EN

Stack Overflow用户

发布于 2010-12-08 22:25:38

我的格式有适度的调整:这个版本是SQL-2005+,可以在没有“rowguidcol”的数据库上运行:

WITH TablesCTE(SchemaName, TableName, TableID, Ordinal) AS
(
    SELECT
        OBJECT_SCHEMA_NAME(so.object_id) AS SchemaName,
        OBJECT_NAME(so.object_id) AS TableName,
        so.object_id AS TableID,
        0 AS Ordinal
    FROM
        sys.objects AS so
    WHERE
        so.type = 'U'
        AND so.is_ms_Shipped = 0
    UNION ALL
    SELECT
        OBJECT_SCHEMA_NAME(so.object_id) AS SchemaName,
        OBJECT_NAME(so.object_id) AS TableName,
        so.object_id AS TableID,
        tt.Ordinal + 1 AS Ordinal
    FROM
        sys.objects AS so
    INNER JOIN sys.foreign_keys AS f
        ON f.parent_object_id = so.object_id
        AND f.parent_object_id != f.referenced_object_id
    INNER JOIN TablesCTE AS tt
        ON f.referenced_object_id = tt.TableID
    WHERE
        so.type = 'U'
        AND so.is_ms_Shipped = 0
)

SELECT DISTINCT
        t.Ordinal,
        t.SchemaName,
        t.TableName,
        t.TableID
    FROM
        TablesCTE AS t
    INNER JOIN
        (
            SELECT
                itt.SchemaName as SchemaName,
                itt.TableName as TableName,
                itt.TableID as TableID,
                Max(itt.Ordinal) as Ordinal
            FROM
                TablesCTE AS itt
            GROUP BY
                itt.SchemaName,
                itt.TableName,
                itt.TableID
        ) AS tt
        ON t.TableID = tt.TableID
        AND t.Ordinal = tt.Ordinal
ORDER BY
    t.Ordinal,
    t.TableName
票数 14
EN

Stack Overflow用户

发布于 2008-12-09 10:06:45

您可以使用迭代算法,它可能比CTE更不复杂。下面是一个根据深度排序的示例:

declare @level int      -- Current depth
       ,@count int      

-- Step 1: Start with tables that have no FK dependencies
--  
if object_id ('tempdb..#Tables') is not null
    drop table #Tables

select s.name + '.' + t.name  as TableName
      ,t.object_id            as TableID
      ,0                      as Ordinal
  into #Tables
  from sys.tables t
  join sys.schemas s
    on t.schema_id = s.schema_id
 where not exists
       (select 1
          from sys.foreign_keys f
         where f.parent_object_id = t.object_id)

set @count = @@rowcount         
set @level = 0


-- Step 2: For a given depth this finds tables joined to 
-- tables at this given depth.  A table can live at multiple 
-- depths if it has more than one join path into it, so we 
-- filter these out in step 3 at the end.
--
while @count > 0 begin

    insert #Tables (
           TableName
          ,TableID
          ,Ordinal
    ) 
    select s.name + '.' + t.name  as TableName
          ,t.object_id            as TableID
          ,@level + 1             as Ordinal
      from sys.tables t
      join sys.schemas s
        on s.schema_id = t.schema_id
     where exists
           (select 1
              from sys.foreign_keys f
              join #Tables tt
                on f.referenced_object_id = tt.TableID
               and tt.Ordinal = @level
               and f.parent_object_id = t.object_id
               and f.parent_object_id != f.referenced_object_id)
                   -- The last line ignores self-joins.  You'll
                   -- need to deal with these separately

   set @count = @@rowcount
   set @level = @level + 1
end

-- Step 3: This filters out the maximum depth an object occurs at
-- and displays the deepest first.
--
select t.Ordinal
      ,t.TableID
      ,t.TableName
  from #Tables t
  join (select TableName     as TableName
              ,Max (Ordinal) as Ordinal
          from #Tables
         group by TableName) tt
    on t.TableName = tt.TableName
   and t.Ordinal = tt.Ordinal
 order by t.Ordinal desc
票数 2
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/352176

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