Question

我有3张如下表：

hr_emp_job_compensation：

    id   date          fkEmp_id  basic_wage    part_hours   part_amt

     1    04-01-2016    1            4500        35          120
     2    04-01-2016    3            3800        30          150
     3    08-01-2016    3            3200        30          100

hr_emp_job_info：

    id    fkEmp_id

     1      1
     2      3

hr_emp_info：

   id    employee_id   first_name

    1     001       Ram
    2     002       Lak
    3     003       jai
    4     004       shiva

我想从表1中选择记录，根据列Date值更高。

我尝试以下查询：

SELECT t1.fkEmp_id,max(t1.date),max(t1.id) as uid,t1.part_hours,t1.part_amt, t3.first_name, t3.employee_id 
FROM `hr_emp_job_compensation` as t1 
inner join `hr_emp_job_info` as t2 on t1.fkEmp_id = t2.fkEmp_id 
left join `hr_emp_info` as t3 on t3.id = t1.fkEmp_id 
group by t1.fkEmp_id

但结果如下所示：

      fkEmp_id    max(t1.date)   uid  part_hours  part_amt  first_name  employee_id
        1          2016-01-04     1     35          120       Ram         001

        3          2016-01-08     3     30          150       Jai         003

这里从id 2中获取part_hours和part_amt列。如何更改查询。

Answer 1

无需为MAX()和date添加id。您可以处理MAX(date)子句中的WHERE。

SELECT  t1.fkEmp_id, t1.date as `date`, t1.id as uid,
        t1.part_hours, t1.part_amt, 
        t3.first_name, t3.employee_id 
FROM `hr_emp_job_compensation` as t1 
INNER JOIN `hr_emp_job_info` as t2 on t2.fkEmp_id = t1.fkEmp_id
LEFT JOIN `hr_emp_info` as t3 on t3.id = t1.fkEmp_id 
WHERE t1.`date`= ( SELECT MAX(`date`) 
                   FROM `hr_emp_job_compensation` 
                   WHERE fkEmp_id = t1.fkEmp_id);

请找到

如何根据mysql

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