USE TESVISCO_ADMIN;

SET @col_exists := (
  SELECT COUNT(*) FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = 'TESVISCO_ADMIN'
    AND TABLE_NAME = 'super_admins'
    AND COLUMN_NAME = 'preferences'
);

SET @sql := IF(@col_exists = 0,
  'ALTER TABLE super_admins ADD COLUMN preferences JSON NULL AFTER last_store_code',
  'SELECT ''preferences column already exists'''
);

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;