循环遍历表并更新记录答案

【问题标题】：Loop through table and update records循环遍历表并更新记录
【发布时间】：2016-04-27 13:33:42
【问题描述】：

我需要根据同一张表中的多个字段修改一个表，但我似乎无法正确处理，这真的很痛苦。

我的桌子是这样的：

    Id      person  code    product     item        delivery
    41      254252  1368    prodname    561352401   23
    41      254252  1368    prodname    4421252401  23
    42      254252  1368    prodname    2501552403  23
    42      254252  1368    prodname    5281352400  23
    45      254251  1368    prodname    561352401   56
    46      254251  1368    prodname    2501552403  56
    49      254250  1368    prodname    561352401   69
    50      254250  1368    prodname    2501552403  69
    1357    253288  1368    prodname    4421252401  2
    1358    253288  1368    prodname    5281352400  2
    1359    253288  1368    prodname    9990070900  2
    1377    253263  1220    prodname    2331252400  11
    1378    253263  1220    prodname    2461252403  11
    1379    253263  1220    prodname    9990070900  11

我需要根据人员、代码和产品更新交付列。当其中一列中的值发生更改时，应将其计数器设置为 0。

我需要输出如下所示：

    Id      person  code    product     item        delivery
    41      254252  1368    prodname    561352401   23
    41      254252  1368    prodname    4421252401  24
    42      254252  1368    prodname    2501552403  25
    42      254252  1368    prodname    5281352400  26
    45      254251  1368    prodname    561352401   56
    46      254251  1368    prodname    2501552403  57
    49      254250  1368    prodname    561352401   69
    50      254250  1368    prodname    2501552403  70
    1357    253288  1368    prodname    4421252401  2
    1358    253288  1368    prodname    5281352400  3
    1359    253288  1368    prodname    9990070900  4
    1377    253263  1220    prodname    2331252400  11
    1378    253263  1220    prodname    2461252403  12
    1379    253263  1220    prodname    9990070900  13

到目前为止我有这个：

    DECLARE @Id     INT
    DECLARE @person     INT
    DECLARE @code       VARCHAR(15)
    DECLARE @product    VARCHAR(10)
    DECLARE @Itemtype   VARCHAR(10)
    DECLARE @Item       VARCHAR(50)
    DECLARE @Delivery   INT

   DECLARE sel_cursor CURSOR FOR

   SELECT Id, person, code, product, delivery FROM [dbo].[orders]
   WHERE Itemtype = 'ART'
   ORDER BY person, product,Itemtype, Item, delivery desc

   DECLARE @Counter     INT 

   OPEN sel_cursor

   set @Counter = 0

   FETCH NEXT FROM sel_cursor
   INTO @Id, @person, @code, @product, @Delivery

   WHILE @@FETCH_STATUS = 0
   BEGIN 

   --WHILE (SELECT COUNT(*) FROM orders WHERE person=@person AND code=@code and product=@product) > 0

   BEGIN
       UPDATE Orders
       SET delivery = (delivery + @Counter) WHERE person=@person AND code=@code AND product=@product

       set @Counter = @Counter + 1
   END

   FETCH NEXT FROM sel_cursor
   INTO  @Id, @person, @code, @product, @Delivery

   set @Counter = 0

    END 

   CLOSE sel_cursor
   DEALLOCATE sel_cursor
   END

【问题讨论】：

标签： sql-server while-loop sql-update iteration

【解决方案1】：

DECLARE @t TABLE (
    Id INT,
    person INT,
    code VARCHAR(10),
    product VARCHAR(20),
    item VARCHAR(20),
    delivery INT
)

INSERT INTO @t
VALUES
    (41  , 254252, 1368, 'prodname', '561352401 ', 23),
    (41  , 254252, 1368, 'prodname', '4421252401', 23),
    (42  , 254252, 1368, 'prodname', '2501552403', 23),
    (42  , 254252, 1368, 'prodname', '5281352400', 23),
    (45  , 254251, 1368, 'prodname', '561352401 ', 56),
    (46  , 254251, 1368, 'prodname', '2501552403', 56),
    (49  , 254250, 1368, 'prodname', '561352401 ', 69),
    (50  , 254250, 1368, 'prodname', '2501552403', 69),
    (1357, 253288, 1368, 'prodname', '4421252401', 2 ),
    (1358, 253288, 1368, 'prodname', '5281352400', 2 ),
    (1359, 253288, 1368, 'prodname', '9990070900', 2 ),
    (1377, 253263, 1220, 'prodname', '2331252400', 11),
    (1378, 253263, 1220, 'prodname', '2461252403', 11),
    (1379, 253263, 1220, 'prodname', '9990070900', 11)

;WITH cte AS 
(
    SELECT *, RowNum = ROW_NUMBER() OVER (
                    PARTITION BY Person, Code, product
                    ORDER BY 1/0) - 1
    FROM @t
)
UPDATE cte
SET delivery += RowNum

SELECT * FROM @t

输出 -

Id          person      code       product    item          delivery
----------- ----------- ---------- ---------- ------------- -----------
41          254252      1368       prodname   561352401     23
41          254252      1368       prodname   4421252401    24
42          254252      1368       prodname   2501552403    25
42          254252      1368       prodname   5281352400    26
45          254251      1368       prodname   561352401     56
46          254251      1368       prodname   2501552403    57
49          254250      1368       prodname   561352401     69
50          254250      1368       prodname   2501552403    70
1357        253288      1368       prodname   4421252401    2
1358        253288      1368       prodname   5281352400    3
1359        253288      1368       prodname   9990070900    4
1377        253263      1220       prodname   2331252400    11
1378        253263      1220       prodname   2461252403    12
1379        253263      1220       prodname   9990070900    13

【讨论】：