Sql-server – How to find all positions of a string within another string

sql serversql-server-2005string-searching

How can I find all the positions with patindex in a table or variable?

declare @name nvarchar(max)
set @name ='ali reza dar yek shabe barani ba yek  '
  + 'dokhtare khoshkel be disco raft va ali baraye'
  + ' 1 saat anja bud va sepas... ali...'
select patindex('%ali%',@name) as pos

This returns 1 but I want all results, e.g.:

pos
===
  1
 74
113

Best Answer

declare @name nvarchar(max)
set @name ='ali reza dar yek shabe barani ba yek  dokhtare khoshkel be disco raft va ali baraye 1 saat anja bud va sepas... ali...'

Declare @a table (pos int)
Declare @pos int
Declare @oldpos int
Select @oldpos=0
select @pos=patindex('%ali%',@name) 
while @pos > 0 and @oldpos<>@pos
 begin
   insert into @a Values (@pos)
   Select @oldpos=@pos
   select @pos=patindex('%ali%',Substring(@name,@pos + 1,len(@name))) + @pos
end

Select * from @a

To make it reuseable you can use it in a table function to call it like:

Select * from  dbo.F_CountPats ('ali reza dar yek shabe barani ba yek  dokhtare khoshkel be disco raft va ali baraye 1 saat anja bud va sepas... ali...','%ali%')

The function could look like this 

Create FUNCTION [dbo].[F_CountPats] 
(
@txt varchar(max),
@Pat varchar(max)
)
RETURNS 
@tab TABLE 
(
 ID int
)
AS
BEGIN
Declare @pos int
Declare @oldpos int
Select @oldpos=0
select @pos=patindex(@pat,@txt) 
while @pos > 0 and @oldpos<>@pos
 begin
   insert into @tab Values (@pos)
   Select @oldpos=@pos
   select @pos=patindex(@pat,Substring(@txt,@pos + 1,len(@txt))) + @pos
end

RETURN 
END

GO
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