Question

我有3张桌子

- Employee (idemployee, iddivision, firstname, lastname)
- Salary (idsalary, idemployee, dateadded, amount)
- division (iddivision, divisionname)

我要显示在1月到4月之间数量最多的名字

到目前为止，我已经尝试过

SELECT firstname, MAX(Total) FROM (
SELECT firstname,SUM(amount) AS Total
FROM salary
JOIN employee ON employee.idemployee=salary.idemployee
WHERE dateadded BETWEEN "2019-1-1" AND "2019-4-1"
GROUP BY employee.idemployee) as t

但是employeeid sql显示错误。为什么？

Answer 1

SELECT employee.firstname, SUM(salary.amount) AS Total
FROM salary
  JOIN employee 
    ON employee.idemployee=salary.idemployee
WHERE salary.dateadded BETWEEN "2019-01-01" AND "2019-04-01"
GROUP BY employee.firstname
ORDER BY 2 DESC
LIMIT 1

您正在按所需范围进行过滤，然后将该范围内的金额求和，并按员工分组。如果您按该总和排序并仅获得第一行，则它必须是您要查找的内容。

更好的是，如果您的员工仅在firstname属性中具有名称，则可能会错误地按相同的名称分组。因此，为了更好地确定员工，我将在idemployee句子中添加group by。像这样：

SELECT employee.idemployee, employee.firstname, SUM(salary.amount) AS Total
FROM salary
  JOIN employee 
    ON employee.idemployee=salary.idemployee
WHERE salary.dateadded BETWEEN "2019-01-01" AND "2019-04-01"
GROUP BY employee.idemployee,employee.firstname
ORDER BY 3 DESC
LIMIT 1

Answer 2

您是说要从最大到最小排序吗？

SELECT firstname, Total FROM (
SELECT firstname,SUM(amount) AS Total
FROM salary
JOIN employee ON employee.idemployee=salary.idemployee
WHERE dateadded BETWEEN "2019-1-1" AND "2019-4-1"
GROUP BY employee.idemployee) as t
order by desc Total

SQL SELECT ID FROM MAX VALUE

2 个答案: