SQL字符串數組操作(轉)

/*
一、按指定符號分割字符串，返回分割後的元素個數，方法很簡單，就是看字符串中存在多少個分隔符號，然後再加一，就是要求的結果。
--Alter function Get_StrArrayLength

create function Get_StrArrayLength
(
@str varchar(5000), --要分割的字符串
@split varchar(10) --分隔符號
)
returns int
as
begin
declare @location int
declare @start int
declare @length int

set @str=ltrim(rtrim(@str))
set @location=charindex(@split,@str)
set @length=1
while @location<>0
begin
set @start=@location+1
set @location=charindex(@split,@str,@start)
set @length=@length+1
end
return @length
end

調用示例：select dbo.Get_StrArrayLength('1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,

36,37,38,39,40,41,42,43,44,45,46,47,48',',')
返回值：48

二、按指定符號分割字符串，返回分割後指定索引的第幾個元素，象數組一樣方便
--alter function Get_StrArrayStrOfIndex

create function Get_StrArrayStrOfIndex
(
@str varchar(5000), --要分割的字符串
@split varchar(10), --分隔符號
@index int --取第幾個元素
)
returns varchar(5000)
as
begin
declare @location int
declare @start int
declare @next int
declare @seed int

set @str=ltrim(rtrim(@str))
set @start=1
set @next=1
set @seed=len(@split)

set @location=charindex(@split,@str)
while @location<>0 and @index>@next
begin
set @start=@location+@seed
set @location=charindex(@split,@str,@start)
set @next=@next+1
end
if @location =0 select @location =len(@str)+1
--這兒存在兩種情況：1、字符串不存在分隔符號 2、字符串中存在分隔符號，跳出while循環後，@location爲0，那默認爲字符串後邊有一個分隔符號。

return substring(@str,@start,@location-@start)
end

調用示例：select dbo.Get_StrArrayStrOfIndex('8,9,4',',',2)
返回值：9

三、結合上邊兩個函數，象數組一樣遍歷字符串中的元素

declare @str varchar(5000)
set @str='1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48'
print dbo.Get_StrArrayLength(@str,',')
declare @next int
set @next=1
while @next<=dbo.Get_StrArrayLength(@str,',')
begin
print dbo.Get_StrArrayStrOfIndex(@str,',',@next) ----輸出數組中的值
set @next=@next+1
end

調用結果：
1
2
3
4
5

四、自己加一個函數，檢查一個元素是否在數組中

Alter function CheckStrInArr(@s as varchar(50),@sArr as varchar(5000)) returns int
as
begin
declare @str varchar(5000)
set @str=@sArr
declare @next int
declare @ret int
set @ret=0
set @next=1
while @next<=dbo.Get_StrArrayLength(@str,',')
begin
if dbo.Get_StrArrayStrOfIndex(@str,',',@next)=@s
begin
set @ret=1;
end
set @next=@next+1
end
return @ret
end