DF048: A procedure parameter or variable is declared but never used.

CREATE PROCEDURE dbo.ProcDemo (
  @LocationId SMALLINT,
  @LocationName NVARCHAR(255)
)
AS
BEGIN
  SET NOCOUNT ON;
 
  SELECT L.LocationID, L.Name
  FROM Production.Location l;
 
  DECLARE @location_count SMALLINT;
  SET @location_count = (
    SELECT COUNT(*) AS count_row
    FROM Production.Location l
  );
END;
GO

CREATE PROCEDURE dbo.ProcDemo (
  @LocationId SMALLINT,
  @LocationName NVARCHAR(255) OUTPUT
)
AS
BEGIN
  SET NOCOUNT ON;
  DECLARE @LocName NVARCHAR(255);
 
  SET @LocName = (
    SELECT l.Name
    FROM Production.Location l
    WHERE l.LocationID = @LocationId
    ORDER BY l.Name
      OFFSET 0 ROWS
      FETCH NEXT 1 ROWS ONLY
  );
 
  SET @LocationName = @LocName;
  RETURN @LocationName;
END;
GO