查找字符在字符串中第N次出现的位置

 

1.查找字符串 @find 在字符串 @str 中第 (@n) 次出现的位置。没有第 (@n) 次返回 0。

 返回@find在@str中第(@n)次出现的位置。没有第(@n)次返回0。

 create function fn_find(@find varchar(8000), @str varchar(8000), @n smallint)
     returns int
 as
 begin
     if @n < 1 return (0)
     declare @start smallint, @count smallint, @index smallint, @len smallint
     set @index = charindex(@find, @str)
     if @index = 0 return (0)
     else select @count = 1, @len = len(@find)
     while @index > 0 and @count < @n
         begin
             set @start = @index + @len
             select @index = charindex(@find, @str, @start), @count = @count + 1
         end
     if @count < @n set @index = 0
     return (@index)
 end
 go
 declare @str varchar(100)
 set @str='A,B,C,D,A,B,C,D,C,D,B,A,C,E'
 select dbo.fn_find('A',@str,1) as one, dbo.fn_find('A',@str,2) as two, dbo.fn_find('A',@str,3) as three, dbo.fn_find('A',@str,4) as four