sql server 表值函数将字符串转为列

Posted 2020-09-29 句号1314

1.标题：将字符串@str变成表中的列

DECLARE @str VARCHAR(8000)
SET @str=\'a,bb,cc,dd,ff,gg\'

SELECT @str,* FROM Func_SplitStrToTable(@str)

 

代码如下：
SET QUOTED_IDENTIFIER ON
SET ANSI_NULLS ON
GO
CREATE FUNCTION [dbo].[Func_SplitStrToTable] ( @str VARCHAR(8000) )
RETURNS @tableName TABLE ( Col VARCHAR(100) )
AS --该函数用于把一个用逗号分隔的多个数据字符串变成一个表的一列，例如字符串\'1,2,3,4,5\' 将转换成一个表

    BEGIN

        SET @str = @str + \',\'

        DECLARE @insertStr VARCHAR(100) --截取后的第一个字符串

        DECLARE @newstr VARCHAR(8000) --截取第一个字符串后剩余的字符串

        SET @insertStr = LEFT(@str, CHARINDEX(\',\', @str) - 1)

        SET @newstr = STUFF(@str, 1, CHARINDEX(\',\', @str), \'\')

        INSERT  @tableName
        VALUES  ( @insertStr )

        WHILE ( LEN(@newstr) > 0 )
            BEGIN

                SET @insertStr = LEFT(@newstr, CHARINDEX(\',\', @newstr) - 1)

                INSERT  @tableName
                VALUES  ( @insertStr )

                SET @newstr = STUFF(@newstr, 1, CHARINDEX(\',\', @newstr), \'\')

            END

        RETURN

    END
GO

 

/*  
2.标题：按某字段合并字符串之一(简单合并)  
3.作者：(十八年风雨,守得冰山雪莲花开)  
4.时间：2008-11-06  
5.地点：广东深圳  
6.  
7.描述：将如下形式的数据按id字段合并value字段。  
8.id    value  
9.----- ------   
10.1     aa  
11.1     bb  
12.2     aaa  
13.2     bbb  
14.2     ccc  
15.需要得到结果：  
16.id     value  
17.------ -----------   
18.1      aa,bb  
19.2      aaa,bbb,ccc  
20.即：group by id, 求 value 的和（字符串相加）  
21.*/  
22.--1、sql2000中只能用自定义的函数解决   
23.create table tb(id int, value varchar(10))  
24.insert into tb values(1, \'aa\')  
25.insert into tb values(1, \'bb\')  
26.insert into tb values(2, \'aaa\')  
27.insert into tb values(2, \'bbb\')  
28.insert into tb values(2, \'ccc\')  
29.go  
30.  
31.create function dbo.f_str(@id varchar(10)) returns varchar(1000)  
32.as  
33.begin  
34.  declare @str varchar(1000)  
35.  select @str = isnull(@str + \',\' , \'\') + cast(value as varchar) from tb where id = @id  
36.  return @str  
37.end  
38.go  
39.  
40.--调用函数   
41.select id , value = dbo.f_str(id) from tb group by id  
42.  
43.drop function dbo.f_str  
44.drop table tb  
45.  
46.  
47.--2、sql2005中的方法   
48.create table tb(id int, value varchar(10))  
49.insert into tb values(1, \'aa\')  
50.insert into tb values(1, \'bb\')  
51.insert into tb values(2, \'aaa\')  
52.insert into tb values(2, \'bbb\')  
53.insert into tb values(2, \'ccc\')  
54.go  
55.  
56.select id, [value] = stuff((select \',\' + [value] from tb t where id = tb.id for xml path(\'\')) , 1 , 1 , \'\')  
57.from tb  
58.group by id  
59.  
60.drop table tb  
61.  
62.  
63.--3、使用游标合并数据   
64.create table tb(id int, value varchar(10))  
65.insert into tb values(1, \'aa\')  
66.insert into tb values(1, \'bb\')  
67.insert into tb values(2, \'aaa\')  
68.insert into tb values(2, \'bbb\')  
69.insert into tb values(2, \'ccc\')  
70.go  
71.declare @t table(id int,value varchar(100))--定义结果集表变量   
72.--定义游标并进行合并处理   
73.declare my_cursor cursor local for  
74.select id , value from tb  
75.declare @id_old int , @id int , @value varchar(10) , @s varchar(100)  
76.open my_cursor  
77.fetch my_cursor into @id , @value  
78.select @id_old = @id , @s=\'\'  
79.while @@FETCH_STATUS = 0  
80.begin  
81.    if @id = @id_old  
82.       select @s = @s + \',\' + cast(@value as varchar)  
83.    else  
84.      begin  
85.        insert @t values(@id_old , stuff(@s,1,1,\'\'))  
86.        select @s = \',\' + cast(@value as varchar) , @id_old = @id  
87.      end  
88.    fetch my_cursor into @id , @value  
89.END  
90.insert @t values(@id_old , stuff(@s,1,1,\'\'))  
91.close my_cursor  
92.deallocate my_cursor  
93.  
94.select * from @t  
95.drop table tb