SQL : in clause in stored procedure:how to pass values

Question

I want to write a SQL Server 2005 stored procedure which will select and return the user records from the user table for some userids which are passed to the stored procedur

Answer 1

Assuming T-SQL, you can use this nice function (that returns a table).

DROP FUNCTION sp_ConvertStringToTable
GO
CREATE FUNCTION sp_ConvertStringToTable(@list ntext)
      RETURNS @tbl TABLE (Position INT IDENTITY(1, 1) NOT NULL,
                          Value INT NOT NULL) AS
   BEGIN
      DECLARE @pos      int,
              @textpos  int,
              @chunklen smallint,
              @str      nvarchar(4000),
              @tmpstr   nvarchar(4000),
              @leftover nvarchar(4000)

      SET @textpos = 1
      SET @leftover = ''
      WHILE @textpos <= datalength(@list) / 2
      BEGIN
         SET @chunklen = 4000 - datalength(@leftover) / 2
         SET @tmpstr = ltrim(@leftover + substring(@list, @textpos, @chunklen))
         SET @textpos = @textpos + @chunklen

         SET @pos = charindex(' ', @tmpstr)
         WHILE @pos > 0
         BEGIN
            SET @str = substring(@tmpstr, 1, @pos - 1)
            INSERT @tbl (Value) VALUES(convert(int, @str))
            SET @tmpstr = ltrim(substring(@tmpstr, @pos + 1, len(@tmpstr)))
            SET @pos = charindex(' ', @tmpstr)
         END

         SET @leftover = @tmpstr
      END

      IF ltrim(rtrim(@leftover)) <> ''
         INSERT @tbl (Value) VALUES(convert(int, @leftover))

      RETURN
   END   
GO

In this way:

SELECT * FROM Users 
WHERE userid IN 
( SELECT Value FROM sp_ConvertStringToTable('1 2 3') )

You can change the stored function to work with comma separated strings instead of space separated ones.

If you don't want / can't use a stored function you can include the code of it inside the stored procedure where needed.

EDIT: this is incredibly more performant than the string concatenation.