Question

我需要一些SQL Server游标的帮助：

     DECLARE @iTerminalID varchar(100)
     DECLARE @iID int
     DECLARE @iDateTB date
     DECLARE @iNom bigint
     DECLARE @iTBtoEOD bigint
     DECLARE @iSal bigint
     DECLARE @iOldNom bigint
     DECLARE @iOldSal bigint
     DECLARE @check int

     DECLARE main_cursor CURSOR FOR
     SELECT
       TerminalId
     FROM AA
     WHERE Nom IS NULL
     GROUP BY TerminalId
     ORDER BY TerminalId

     OPEN main_cursor
     FETCH NEXT
     FROM main_cursor INTO @iTerminalID
     WHILE (@@fetch_status = 0)

     BEGIN

       SET @iOldSal = 0

       DECLARE detail_cursor CURSOR FOR
       SELECT
         ROW_NUMBER() OVER (ORDER BY TerminalId, DateTB) NoID,
         DateTB,
         Nomi,
         TBtoEOD,
         Sal
       FROM AA
       WHERE TerminalId = @iTerminalID

       OPEN detail_cursor
       FETCH NEXT
       FROM detail_cursor INTO @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal
       WHILE (@@fetch_status = 0)
       BEGIN
         IF  @iNom IS NULL AND @iID = 1        
         BEGIN
           UPDATE AA
           SET Nom = 0
           WHERE TerminalId = @iTerminalID
           AND CONVERT(date, TanggalTB) = CONVERT(date, @iDateTB)        
           SET @iOldSal = abs(@iTBtoEOD)
         END
         ELSE IF @iNom IS NULL
           AND @iID <> 1
           --AND @iOldSal <> 0
         BEGIN
           UPDATE AA
           SET Nom = @iOldSal
           WHERE TerminalId = @iTerminalID
           AND CONVERT(date, DateTB) = CONVERT(date, @iDateTB)
           PRINT concat(@iTerminalID, '----', @iDateTB)
           SET @iOldSal = @iNom - @iTBtoEOD
         END
         ELSE
         BEGIN
           SET @iOldSal = @iNom - @iTBtoEOD
         END

         FETCH detail_cursor INTO @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal
       END
       CLOSE detail_cursor
       DEALLOCATE detail_cursor

       FETCH main_cursor INTO @iTerminalID
     END
     CLOSE main_cursor
     DEALLOCATE main_cursor

我有2个游标用于循环到详细数据的第一个游标在我得到我所拥有的数据的详细信息之后，我将根据我编写的计算执行更新

直到光标到2

完成更新过程后才能解决此问题

Answer 1

正如marc_s所建议的那样，除非你别无选择，否则最好除掉SQL Server开发解决方案中的SQL cursor。

我准备了以下T-SQL Update命令，其中没有使用游标

UPDATE AA
set 
    Nomi = case when ( (NewAA.NoID = 1) and (AA.Nomi is null) ) 
            then 0 
            when ( (NewAA.NoID > 1) and (AA.Nomi is null) )
            then (select sum(t.Nomi) from AA t where t.DateTB < AA.DateTB and t.TerminalId = AA.TerminalId)
            else AA.Nomi
        end 
FROM AA
Inner Join (
    SELECT
        PK_Field,
        NoID = ROW_NUMBER() OVER (Partition By TerminalId ORDER BY DateTB),
        DateTB,
        Nomi,
        TBtoEOD,
        Sal
    FROM AA
) NewAA 
    on AA.PK_Field = NewAA.PK_Field

请注意，我使用了名为PK_Field的主键字段。我希望你的桌子上有主键AA

我不确定Update语句的详细信息，请先在测试环境中测试上面的sql代码

Answer 2

审查每一步的差异

第1步

指定光标的类型/方向

不是group_by而是分明，不要迷惑自己

in row_number在通过单个@iTerminalId
过滤时由TerminalId进行不必要的排序
为抓取和其他陈述保存相同的语法

看起来你需要按升序排列row_numbered - 你必须明确指定order_by

DECLARE
    @main_cursor    cursor,
    @detail_cursor  cursor

 SET @main_cursor = CURSOR FAST_FORWARD FOR
 SELECT DISTINCT
   TerminalId
 FROM AA
 WHERE Nom IS NULL
 ORDER BY TerminalId

 OPEN @main_cursor

 FETCH NEXT FROM @main_cursor
 INTO @iTerminalID

 WHILE (@@fetch_status = 0)
 BEGIN
   SET @iOldSal = 0

   SET @detail_cursor = CURSOR FAST_FORWARD FOR
   SELECT
     ROW_NUMBER() OVER (ORDER BY DateTB) as NoID,
     DateTB, Nomi, TBtoEOD, Sal
   FROM AA
   WHERE TerminalId = @iTerminalID
   ORDER BY NoID

   OPEN @detail_cursor

   FETCH NEXT FROM @detail_cursor
   INTO @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal

   WHILE (@@fetch_status = 0)
   BEGIN
     ... same inner part for now

     FETCH NEXT FROM @detail_cursor
     INTO @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal
   END
   CLOSE @detail_cursor
   DEALLOCATE @detail_cursor

   FETCH NEXT FROM @main_cursor
   INTO @iTerminalID
 END
 CLOSE @main_cursor
 DEALLOCATE @main_cursor

第2步

外部循环除了归零@iOldSal
之外什么都不做
另一件事 - row_number以1为每个TerminalID
开头
所以正确顺序所需的所有数据都可以通过单一查询获得

SET @detail_cursor = CURSOR FAST_FORWARD FOR
SELECT
  a.TerminalId,
  ROW_NUMBER() OVER (PARTITION BY a.TerminalId ORDER BY a.DateTB) as NoID,
  a.DateTB, a.Nomi, a.TBtoEOD, a.Sal
FROM AA a
ORDER BY a.TerminalId, NoID

OPEN @detail_cursor

FETCH NEXT FROM @detail_cursor
INTO @TerminalId, @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal

WHILE (@@fetch_status = 0)
BEGIN
  if @iID = 1
    SET @iOldSal = 0

  ... same inner part for now

  FETCH NEXT FROM @detail_cursor
  INTO @TerminalId, @iID, @iDateTB, @iNom, @iTBtoEOD, @iSal
END
CLOSE @detail_cursor
DEALLOCATE @detail_cursor

第3步

以下更改我假设您在DateTB顺序中为每个终端重新编号行并且您在第一次更新时有拼写错误（TanggalTB列而不是DateTB）并且TBtoEOD是某种始终为负的偏移量并且每次更新只影响一行。这些假设可能不正确 - 请在评论中随意注明。

@iOldSal计算总是相同的，除了@ iNum = NULL，可以借助IsNull（）来处理

当@ iID = 1时@iOldSal始终为0所以首先IF没有意义 - 它与第二个相同

当@iNom为NULL时@iNom - @iTBtoEOD将返回NULL - 您必须初始化它

光标处理意味着您确实有一个光标位于当前处理的行上，因此您不必在更新中再次找到它   声明;但是你需要修改游标类型（FAST_FORWARD包含   READONLY）FORWARD_ONLY（可能是FOR_UPDATE - 只是可以＆＃39; t   记得;可能是sqlserver不允许它是＆＃34; FOR_UPDATE＆＃34;   因为窗口功能，我没有检查）

许多变量变得不必要，因为我们直接引用行值而不需要重复搜索当前处理的行

SET @detail_cursor = CURSOR FORWARD_ONLY, FOR_UPDATE FOR
SELECT
  ROW_NUMBER() OVER (PARTITION BY a.TerminalId ORDER BY a.DateTB) as NoID,
  a.Nom
FROM AA a
ORDER BY a.TerminalId, NoID

FETCH NEXT FROM @detail_cursor
INTO @iID, @iNom

WHILE (@@fetch_status = 0)
BEGIN
  IF @iID = 1
    SET @iOldSal = 0

  UPDATE a SET
    Nom = IsNull(a.Nom, @iOldSal),
    @iOldSal = a.Nom - a.TBtoEOD
  FROM AA a
  WHERE CURRENT OF @detail_cursor

  FETCH NEXT FROM @detail_cursor
  INTO @iID, @iNom
END
CLOSE @detail_cursor
DEALLOCATE @detail_cursor

第4步

所以你只是根据先前编号的行设置一个不具备它的行？不确定我是否理解一切正确，但在我看来，这个任务可以用这样的代码完成：

;WITH cteAA as
(
  SELECT
    a.TerminalID, a.TBtoEOD, a.Nom,
    ROW_NUMBER() OVER (PARTITION BY a.TerminalId ORDER BY a.DateTB, a.Nom) as NoID
  FROM AA a
),
cteAANums as
(
  SELECT a.TerminalID, a.NoID, IsNull(a.Nom, 0) as Nom, a.TBtoEOD
  FROM cteAA a
  WHERE a.NoID = 1

  UNION ALL

  SELECT a.TerminalID, a.NoID, IsNull(a.Nom, n.Nom-n.TBtoEOD) as Nom, a.TBtoEOD
  FROM cteAA a
  INNER JOIN cteAANums n on n.TerminalID = a.TerminalID
  WHERE a.NoID = n.NoID + 1
)
UPDATE a SET
  Nom = n.Nom
FROM AA a
INNER JOIN cteAANums n on n.TerminalID = a.TerminalID and a.DateTB = n.DateTB

没有自连接就无法实现，对于其他情况，光标可能不是一个糟糕的选择。但不是唯一肯定的。

游标循环SQL Server

2 个答案:

第1步

第2步

第3步

第4步