USE trainer_attendance;

SET @col := (
  SELECT COUNT(*) FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'users' AND COLUMN_NAME = 'is_active'
);
SET @sql := IF(@col = 0,
  'ALTER TABLE users ADD COLUMN is_active TINYINT(1) NOT NULL DEFAULT 1 AFTER role',
  'SELECT 1');
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;