[Column 'id' in where clause is ambiguous] sql错误

该字段在关联表中的出现不止一次，不知道应该查哪一张表。只需在where中加上表名即可

 

select source.*, t1.username as targetUserName, t2.username as sourceName from sys_message source
    left join sys_user t1 on source.target_user_id = t1.id
    left join sys_user t2 on source.source_user_id = t2.id
    where source.id=1