mysql左连接left join查询为什么报错？

left join 
(
    select emp_id,group_concat(skill_name SEPARATOR ';') skill
    from skill_info si
    left join (
            select skill_id,emp_id from emp_skill where emp_id in(
                            select uid from sys_user where depart='04'
            )
    ) es on si.id = es.skill_id
) temp on o.empno=u.empno

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[Err] 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'from sys_user u
left join repair_order o on u.empno = o.empno
left join 
(
    ' at line 6