mysql错误：[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggr

Posted 2020-10-30 Yemilice

今天迁移django数据库的时候，跑程序的时候出现这样的错误：

[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column ‘information_schema.
PROFILING.SEQ‘ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

没遇到过这样的问题，所以我把它记录下来，免得以后再次遇到。

先直接上解决办法吧，原理分析在后面，愿意看就看，不愿意这有解决办法，绝对管用。
""修改sql_mode的值,去掉ONLY_FULL_GROUP_BY""

进入你的mysql：

mysql -uxxx -pxxxxx

执行命令:

set @@global.sql_mode        =‘NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION‘;

这样就好了。

现在说一下原理，首先我是怎么出这个问题了呢，是我升级了自己的mysql到5.7，然后原来5.6的一些旧语法就出了这样或者那样的问题，mysql5.7.5后，ONLY_FULL_GROUP_BY 默认为真，那么此时select中的字段必须出现在group by中，所以显而易见，旧新版本的问题。

官方文档在此：
A new function, ANY_VALUE(), is available that can be used to force
MySQL to accept queries that it thinks should be rejected with
ONLY_FULL_GROUP_BY enabled. The function return value and type are
the same as the return value and type of its argument, but the
function result is not checked for the ONLY_FULL_GROUP_BY SQL mode.
If you find that having ONLY_FULL_GROUP_BY enabled causes queries for existing applications to be rejected, either of these actions should restore operation:
If it is possible to modify an offending query, do so, either so that
nondeterministic nonaggregated columns are functionally dependent on
GROUP BY columns, or by referring to nonaggregated columns using
ANY_VALUE().
If it is not possible to modify an offending query (for example, if
it is generated by a third-party application), set the sql_mode
system variable at server startup to not enable ONLY_FULL_GROUP_BY.
For more information about SQL modes and GROUP BY queries, see Server SQL Modes, and MySQL Handling of GROUP BY. (Bug #18486310)