2

我需要将一列中的前半部分单词存储在另一列中。我可以假设有偶数个单词。我使用游标和我发现的一个函数来完成它，该函数接受一个字符串并使用分隔符将其解析为表。

drop table #test
create table #test (id int identity, my_name varchar(128), cleaned_name varchar(128))

insert into #test (my_name) VALUES ('abcd efgh abcd1 efgh1')
insert into #test (my_name) VALUES ('name1 name2 name1a name2a')
insert into #test (my_name) VALUES ('one two one* two*')

select *
from #test


DECLARE @HalfName varchar(100)
DECLARE @i varchar(100)
set @i = 1
while @i <= (select count(*) from #test)
begin
      SELECT @HalfName = COALESCE(@HalfName + ' ', '') + aa.WORD
      FROM (select top (select count(*) / 2 from dm_generic.dbo.GETALLWORDS((select [my_name]
      from #test 
      where id = @i), ' ')) *
      from dm_generic.dbo.GETALLWORDS(
      (select [my_name]
      from #test 
      where id = @i), ' ') 
      ) aa

      update #test 
      set cleaned_name = @HalfName 
      where id = @i

      set @i = @i + 1
      set @HalfName = ''
end

select *
from #test

我试图在没有光标的情况下做到这一点：

UPDATE bb
   SET cleaned_name =
          (SELECT COALESCE (bb.cleaned_name + ' ', '') + aa.WORD
             FROM (SELECT TOP (SELECT count (*) / 2
                                 FROM dm_generic.dbo.GETALLWORDS (
                                         (SELECT [my_name]
                                            FROM #test a
                                           WHERE a.id = bb.id),
                                         ' '))
                          *
                     FROM dm_generic.dbo.GETALLWORDS ( (SELECT [my_name]
                                                          FROM #test b
                                                         WHERE b.id = bb.id),
                                                      ' ')) aa)
  FROM #test bb

我得到的是：

Msg 512, Level 16, State 1, Line 1
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
The statement has been terminated.

任何帮助将不胜感激。

感谢所有响应者，我终于使用@BradC 的这个解决方案来酿造我自己的解决方案，这里是：

update updated
set cleaned_name = (
SELECT Clean
FROM #test AS extern
CROSS APPLY
( 
select TOP (SELECT count (*) / 2 
            FROM dm_generic.dbo.GETALLWORDS (
                                           (SELECT [my_name]
                                            FROM #test a
                                            WHERE a.id = extern.id), ' '))
WORD + ' '
FROM dm_generic.dbo.GETALLWORDS (
         (SELECT [my_name]
            FROM #test a
           WHERE a.id = extern.id),
         ' ')
    FOR XML PATH('')
) pre_trimmed (Clean)
where extern.id = updated.id)
from #test updated

@Nikola Markovinović 解决方案也很有效。

4

2 回答 2

1

局部变量连接技巧在没有局部变量的情况下不起作用 - 您正在使用 @HalfName 连接来自 GETALLWORDS 的单词，但它不适用于使用列名（在这种情况下为 cleaned_name）。要使其工作，您应该使用xml 路径连接技巧。

因此，如果您使用的是 Sql Server 2005 或更高版本，请尝试以下操作：

UPDATE bb
   SET cleaned_name =
      (SELECT stuff ((SELECT TOP (SELECT count (*) / 2 
                                   FROM dm_generic.dbo.GETALLWORDS (
                                         (SELECT [my_name]
                                            FROM #test a
                                           WHERE a.id = bb.id),
                                         ' ')
                                  )
                             ' ' + aa.my_name
                        FROM dm_generic.dbo.GETALLWORDS (
                                         (SELECT [my_name]
                                            FROM #test a
                                           WHERE a.id = bb.id),
                                         ' ') aa 
                         FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
                     , 1, 1, '')
      )
  FROM #test bb

免责声明：我无法对此进行测试。首先仅使用 UDF 进行尝试，然后将其合并到查询中。

更新：我放错了括号 - 最后一行中的第一个右括号应该被删除，并且应该在最后一个之后附加一个。

于 2012-04-10T09:56:11.513 回答
0

创建以下函数

ALTER FUNCTION [dbo].[halfWords]
    (
      @InputString VARCHAR(4000)
    )
RETURNS VARCHAR(4000)
AS BEGIN

    DECLARE @Index INT
    DECLARE @Char CHAR(1)
    DECLARE @PrevChar CHAR(1)
    DECLARE @WordCount INT
    DECLARE @WordCount2 INT
    DECLARE @firstHalf varchar(4000)

    SET @Index = 1
    SET @WordCount = 0

    WHILE @Index <= LEN(@InputString)
        BEGIN
            SET @Char = SUBSTRING(@InputString, @Index, 1)
            SET @PrevChar = CASE WHEN @Index = 1 THEN ' '
                                 ELSE SUBSTRING(@InputString, @Index - 1, 1)
                            END

            IF @PrevChar = ' '
                AND @Char != ' ' 
                SET @WordCount = @WordCount + 1

            SET @Index = @Index + 1
            SET @wordcount2 = ( @wordcount / 2 )
        END


    SET @wordcount = 0 
    SET @Index = 1
    WHILE @Index <= LEN(@InputString)
        BEGIN
            SET @Char = SUBSTRING(@InputString, @Index, 1)
            SET @PrevChar = CASE WHEN @Index = 1 THEN ' '
                                 ELSE SUBSTRING(@InputString, @Index - 1, 1)
                            END

            IF @PrevChar = ' '
                AND @Char != ' ' 
                SET @WordCount = @WordCount + 1


            IF ( @wordcount2 = @WordCount ) 
                BEGIN
                    SET @firstHalf = SUBSTRING(@InputString, 0, @Index) 

                END
            SET @Index = @Index + 1

        END
    RETURN @firstHalf
   END

然后在下面的更新查询中使用它

  UPDATE    #test
  SET       cleaned_name = dbo.[halfWords] (my_name)

选择查询以供参考

SELECT dbo.halfWords ('one two three four five six seven eight')

将返回

one two three four
于 2012-04-10T11:18:03.023 回答