text: DROP PROCEDURE IF EXISTS `proc_get_eid_lab_tat`;
  DELIMITER //
  CREATE PROCEDURE `proc_get_eid_lab_tat`
  (IN filter_year INT(11), IN from_month INT(11), IN to_year INT(11), IN to_month INT(11))
  BEGIN
    SET @QUERY =    "SELECT
                      `ls`.`lab`, `l`.`labname` AS `name`, AVG(`ls`.`tat1`) AS `tat1`,
                      AVG(`ls`.`tat2`) AS `tat2`, AVG(`ls`.`tat3`) AS `tat3`,
                      AVG(`ls`.`tat4`) AS `tat4`
                  FROM `lab_summary` `ls`
                  LEFT JOIN `labs` `l`
                  ON `l`.`ID` = `ls`.`lab` 
                  WHERE 1 ";
  
  
      IF (from_month != 0 && from_month != '') THEN
        IF (to_month != 0 && to_month != '' && filter_year = to_year) THEN
              SET @QUERY = CONCAT(@QUERY, " AND `year` = '",filter_year,"' AND `month` BETWEEN '",from_month,"' AND '",to_month,"' ");
          ELSE IF(to_month != 0 && to_month != '' && filter_year != to_year) THEN
            SET @QUERY = CONCAT(@QUERY, " AND ((`year` = '",filter_year,"' AND `month` >= '",from_month,"')  OR (`year` = '",to_year,"' AND `month` <= '",to_month,"') OR (`year` > '",filter_year,"' AND `year` < '",to_year,"')) ");
          ELSE
              SET @QUERY = CONCAT(@QUERY, " AND `year` = '",filter_year,"' AND `month`='",from_month,"' ");
          END IF;
      END IF;
      ELSE
          SET @QUERY = CONCAT(@QUERY, " AND `year` = '",filter_year,"' ");
      END IF;
        
  
    SET @QUERY = CONCAT(@QUERY, " GROUP BY `ls`.`lab` ");
      SET @QUERY = CONCAT(@QUERY, " ORDER BY `ls`.`lab` ");
  
      PREPARE stmt FROM @QUERY;
      EXECUTE stmt;
  END //
  DELIMITER ;
  