【处理】Table is specified twice, both as a target for 'UPDATE' and as a separate source for data

【错误内容】：Error Code: 1093. Table '表名' is specified twice, both as a target for 'UPDATE' and as a separate source for data

【错产生经过】：update t_test1 set col1= col1_value where val1 in(select val1 from t_test2 group by val1);

【解决办法】：update t_test1 set col1= col1_value where val1 in(select * from (select val1 from t_test2 group by val1) as T);

注意：经测试delete时，也存在这种情况