Помогите решить проблему создания столбца в таблице при установке плагина?

$result = $db->query("SHOW COLUMNS FROM ".PREFIX."_post WHERE Field = 'region_id'");
if(!$result->num_rows) $db->query("ALTER TABLE ".PREFIX."_post ADD `region_id` VARCHAR(190) DEFAULT NULL");
$db->close();

DROP PROCEDURE IF EXISTS RegionID;
DELIMITER //
CREATE PROCEDURE RegionID()
BEGIN
  IF NOT EXISTS (
    SELECT * FROM information_schema.columns
    WHERE table_name = 'dle_post' AND column_name = 'region_id'
  ) THEN
    ALTER TABLE `dle_post` ADD `region_id` VARCHAR(190) DEFAULT NULL;
  END IF;
END //
DELIMITER ;
CALL RegionID();

SET @preparedStatement = (SELECT IF(
  (
    SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
    WHERE
      (table_name = "{prefix}_post")
      AND (table_schema = DATABASE())
      AND (column_name = "region_id")
  ) > 0,
  "SELECT 1",
  CONCAT("ALTER TABLE ", "{prefix}_post", " ADD ", "region_id", " VARCHAR(190) DEFAULT NULL;")
));
PREPARE alterIfNotExists FROM @preparedStatement;
EXECUTE alterIfNotExists;
DEALLOCATE PREPARE alterIfNotExists;

SET @preparedStatement = (SELECT IF(
  (
    SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
    WHERE
      (table_name = "{prefix}_post")
      AND (table_schema = DATABASE())
      AND (column_name = "region_id")
  ) > 0,
  "SELECT 1",
  CONCAT("ALTER TABLE ", "{prefix}_post", " ADD ", "region_id", " VARCHAR(190) DEFAULT NULL;")
));
PREPARE alterIfNotExists FROM @preparedStatement;
EXECUTE alterIfNotExists;
DEALLOCATE PREPARE alterIfNotExists;