SQL 常见问题汇总，持续更新

1. order by 别名报错“Unknown column 't.gsort' in 'order clause'”

错误写法:select id, (c1 + c2) as s from t1 order by t1.s desc

换种写法:select id, (c1 + c2) as s from t1 order by (c1 + c2) desc