Question

我有一个包含名称值对的varchar(max)字段，在每行中都有名称UnderScore Value。

我需要对它进行查询，以便它返回两列中的Name，Value对（因此通过解析文本，删除下划线和“new line”char。

所以从这个

select NameValue from Table

我收到此文：

Name1_Value1
Name2_Value2
Name3_Value3

我想有这个输出

Names  Values
=====  ======
Name1  Value1
Name2  Value2
Name3  Value3

Answer 1

SELECT substring(NameValue, 1, charindex('_', NameValue)-1) AS Names, 
  substring(NameValue, charindex('_', NameValue)+1, LEN(NameValue)) AS Values
FROM Table

修改：将这样的函数或存储过程与临时表结合起来应该适用于多行，具体取决于行分隔符，您还应该在开始之前删除CHAR(13)：

DECLARE @helper varchar(512) DECLARE @current varchar(512) SET @helper = NAMEVALUE WHILE CHARINDEX(CHAR(10), @helper) > 0 BEGIN SET @current = SUBSTRING(@helper, 1, CHARINDEX(CHAR(10), NAMEVALUE)-1) SELECT SUBSTRING(@current, 1, CHARINDEX('_', @current)-1) AS Names, SUBSTRING(@current, CHARINDEX('_', @current)+1, LEN(@current)) AS Names SET @helper = SUBSTRING(@helper, CHARINDEX(CHAR(10), @helper)+1, LEN(@helper)) END SELECT SUBSTRING(@helper, 1, CHARINDEX('_', @helper)-1) AS Names, SUBSTRING(@helper, CHARINDEX('_', @helper)+1, LEN(@helper)) AS Names

Answer 2

 DECLARE @TExt NVARCHAR(MAX)= '***[ddd]***
    dfdf
    fdfdfdfdfdf
    ***[fff]***
    4545445
    45454
    ***[ahaASSDAD]***

    DFDFDF
    ***[SOME   TEXT]***
    '

    DECLARE @Delimiter VARCHAR(1000)= CHAR(13) + CHAR(10) ;
    WITH    numbers
              AS ( SELECT   ROW_NUMBER() OVER ( ORDER BY o.object_id, o2.object_id ) Number
                   FROM     sys.objects o
                            CROSS JOIN sys.objects o2
                 ),
            c AS ( SELECT   Number CHARBegin ,
                            ROW_NUMBER() OVER ( ORDER BY number ) RN
                   FROM     numbers
                   WHERE    SUBSTRING(@text, Number, LEN(@Delimiter)) = @Delimiter
                 ),
            res
              AS ( SELECT   CHARBegin ,
                            CAST(LEFT(@text, charbegin) AS NVARCHAR(MAX)) Res ,
                            RN
                   FROM     c
                   WHERE    rn = 1
                   UNION ALL
                   SELECT   c.CHARBegin ,
                            CAST(SUBSTRING(@text, res.CHARBegin,
                                           c.CHARBegin - res.CHARBegin) AS NVARCHAR(MAX)) ,
                            c.RN
                   FROM     c
                            JOIN res ON c.RN = res.RN + 1
                 )
        SELECT  *
        FROM    res

Answer 3

他是一个你可以使用的例子：

-- Creating table:
create table demo (dID int, dRec varchar(100));

-- Inserting records:
insert into demo (dID, dRec) values (1, 'BCQP1 Sam');
insert into demo (dID, dRec) values (2, 'BCQP2 LD');

-- Selecting fields to retrive records:
select * from demo;

然后我想在一行中显示两行合并，只显示左侧的值，删除右侧的名称，直到空格字符。

    /*
    The STUFF() function puts a string in another string, from an initial position.  
    The LEFT() function returns the left part of a character string with the specified number of characters. 
    The CHARINDEX() string function returns the starting position of the specified expression in a character string. 
*/
SELECT 
 DISTINCT
   STUFF((SELECT ' ' + LEFT(dt1.dRec, charindex(' ', dt1.dRec) - 1) 
          FROM demo dt1
          ORDER BY dRec
          FOR XML PATH('')), 1, 1, '') [Convined values]
FROM demo dt2
--
GROUP BY dt2.dID, dt2.dRec
ORDER BY 1

正如您在运行该函数时所看到的那样，输出将是：

BCQP1 BCQP2

在脚本的顶部，我解释了每个函数的用途（STUFF（），LEFT（），CHARINDEX（）函数）我还使用了DISTINCT来消除重复值。

注意：dt代表＆＃34;演示表＆＃34;，我使用相同的表并使用两个别名dt1和dt2，而dRec代表＆＃34;演示记录＆＃34;

如果您想了解更多有关STUFF（）的信息，请点击此链接：

https://www.mssqltips.com/sqlservertip/2914/rolling-up-multiple-rows-into-a-single-row-and-column-for-sql-server-data/

Answer 4

使用CTE，如果超过100项

，则会出现递归问题

Msg 530，Level 16，State 1，Line 20声明终止。该在语句完成之前，最大递归100已经用尽。

DECLARE @TExt NVARCHAR(MAX)
SET @TExt = '100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203'


DECLARE @Delimiter VARCHAR(1000)= ',';
WITH    numbers
          AS ( SELECT   ROW_NUMBER() OVER ( ORDER BY o.object_id, o2.object_id ) Number
               FROM     sys.objects o
                        CROSS JOIN sys.objects o2
             ),
        c AS ( SELECT   Number CHARBegin ,
                        ROW_NUMBER() OVER ( ORDER BY number ) RN
               FROM     numbers
               WHERE    SUBSTRING(@text, Number, LEN(@Delimiter)) = @Delimiter
             ),
        res
          AS ( SELECT   CHARBegin ,
                        CAST(LEFT(@text, charbegin) AS NVARCHAR(MAX)) Res ,
                        RN
               FROM     c
               WHERE    rn = 1
               UNION ALL
               SELECT   c.CHARBegin ,
                        CAST(SUBSTRING(@text, res.CHARBegin,
                                       c.CHARBegin - res.CHARBegin) AS NVARCHAR(MAX)) ,
                        c.RN
               FROM     c
                        JOIN res ON c.RN = res.RN + 1
             )
    SELECT  *
    FROM    res

如何解析字符串并从中创建多个列？

4 个答案: