SELECT a.*,c.orgName AS dutyOrgNames,GROUP_CONCAT(e.userName) AS projectLeaderNames
FROM majorProject a
LEFT JOIN projectdutyorg b ON (a.id = b.projectId)
LEFT JOIN organization c ON (c.id = b.orgId)
LEFT JOIN projectleader d ON (d.projectId = a.id)
LEFT JOIN userinfo e ON (e.id = d.userId)
WHERE 1=1 AND a.isDelete = 0
GROUP BY a.id
这是之前写的一段sql，会提示错误：
Expression #23 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'dcdb_guangan_190815.c.ORGNAME' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
如果在group by a.id后面加上",c.orgName"则查询成功，但是无法达到之前sql想要的结果。
我尝试解析新group by的用法，最开始同事告诉我使用group by时，必须和select字段一致，或者使用分组函数max之类的。但是我修改代码后：
SELECT a.*,GROUP_CONCAT(e.userName) AS projectLeaderNames
FROM majorProject a
LEFT JOIN projectdutyorg b ON (a.id = b.projectId)
LEFT JOIN organization c ON (c.id = b.orgId)
LEFT JOIN projectleader d ON (d.projectId = a.id)
LEFT JOIN userinfo e ON (e.id = d.userId)
WHERE 1=1 AND a.isDelete = 0
GROUP BY a.id
这段sql运行成功了，但让我不解的是a.星号里面包含了很多字段，并没有和group by后面的字段一致。之后我认为，应该是a.id是主键的原因，将a.星号中的一个字段也加上主键标识，出现了错误：
Expression #23 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'dcdb_guangan_190815.a.RECORDRECORDCREATETIME' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
a.RECORDCREATETIME是a.*中的一个字段。
我总结为：如果select字段中存在主键字段，那么必须与group by后面一致。但是问题在于，最开始出现的报错c.orgName，这个字段并不是主键字段。
非常迷惑，望各位大佬解答，在网上搜了一些资料，都只说如何解决，但是解决方案最佳也仅仅是改配置文件，对我来说这样的解决方法不太友好，我希望理解group by的用法，通过修改sql去解决这个问题。
