Question

UPDATE
    dbo.FormDetail
SET 
    FieldOrder=FieldOrder+1
WHERE
    WHERE DocCode IN (1,2,3)
    AND FieldOrder >= (SELECT FieldOrder FROM dbo.FormDetail
                       WHERE FieldData LIKE '%OldField%'
                       AND DocCode IN (1,2,3))

不知道我在这里尝试做的有多清楚，但是我想在FieldOrder表中为FormDetail表增加一些文档，但仅限于某个字段之后（基本上所以我有一个空隙来插入一个新的领域）。但显而易见的问题是，我FieldOrder中的Where不会特定于该语句当前可能正在更新的文档。我认为可能使用分区，但我只在partitions部分使用From。任何帮助都会非常感激。

更新

dbo.FormDetail示例数据

DocCode FieldOrder FieldData

1 1'标题'

1 2'OldField'

1 3'签名'

2 1'段落'

2 2'OldField'

3 1'OldField'

Answer 1

在现有代码中，您的子查询会执行一次并将所有结果返回到外部查询。

您实际看起来想要的是对于外部查询正在处理的每一行执行一次子查询。它被称为相关子查询。

为了让它像我一样工作，我做了两处改变;
我在子查询中给了表一个别名 2.我已经更改了子查询WHERE子句以引用外部查询

中的表

UPDATE
  dbo.FormDetail
SET
  FieldOrder=FieldOrder+1
WHERE
  DocCode IN (1,2,3)
  AND FieldOrder >= (SELECT lookup.FieldOrder
                       FROM dbo.FormDetail AS lookup
                      WHERE lookup.FieldData LIKE '%OldField%'
                        AND lookup.DocCode = FormDetail.DocCode
                    )

另一种选择可能是加入子查询...

UPDATE
  FormDetail
SET
  FieldOrder=FieldOrder+1
FROM
  dbo.FormDetail
INNER JOIN
(
  SELECT
    DocCode,
    FieldOrder
  FROM
    dbo.FormDetail
  WHERE
    DocCode IN (1,2,3)
    AND FieldData LIKE '%OldField%'
)
  AS lookup
    ON  lookup.DocCode     = FormDetail.DocCode
    AND lookup.FieldOrder >= FormDetail.FieldOrder

Answer 2

你得到什么错误？我唯一看错的是你不限制你的子查询。在大型数据集上，它可能有点低效，但目前您需要的只是一个MIN（）;

DECLARE @FormDetail TABLE(
    DocCode         INT
,   Fieldorder      INT
,   FieldData       NVARCHAR(MAX)
)

INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (1,1, 'Title')
INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (1,2, 'OldField')
INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (1,3, 'Signature')
INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (2,1, 'Paragraph')
INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (2,2, 'OldField')
INSERT INTO @FormDetail (DocCode, FieldOrder, FieldData) VALUES (3,1, 'OldField')


UPDATE @FormDetail SET      
    FieldOrder = FieldOrder + 1 
WHERE 
    DocCode IN (1,2,3)     
AND FieldOrder >= (
    SELECT MIN(FieldOrder) FROM @FormDetail                        
    WHERE FieldData LIKE '%OldField%'                        
    AND DocCode IN (1,2,3)
) 

SELECT * FROM @FormDetail

给出以下内容：

1 2标题

1 3 OldField

1 4签名

2 2段

2 3 OldField

3 2 OldField

你想要的只是在某一点之后增加你的田径顺序，对吗？

结合声明

2 个答案: