Question

我在组合两个MySQL查询并获取正确的数据时遇到了很多麻烦。

我的第一个查询如下：

SELECT e.employee_id,
    e.employee_name,
    COUNT(s.sale_id) AS employee_sales
FROM employees e,
    sales s,
    days d
WHERE s.sale_id = '$sale_type'
    AND d.day_year_id = '$year'
    AND s.sale_day_id = d.day_id
    AND e.employee_id = s.sale_employee_id
GROUP BY e.employee_id

然后，在每个员工结果上，我执行三个查询以获取有关每个员工的具体信息：

首先，为了获得他们工作的总分钟数，我执行以下查询。当我尝试将第一个与第一个一起加入时，无论他们是否在特定日期进行了销售，我都无法返回他们工作的所有会议记录：

SELECT SUM(employee_day_end_minute-employee_day_start_minute) AS employee_minutes
FROM employee_days ed,
    days d
WHERE ed.employee_days_employee_id = '$employee_id'
    AND ed.employee_days_day_id = d.day_id
    AND d.day_year_id = '$year'

其次，要获得他们最有效的工作类型：

SELECT ed.employee_day_position,
    COUNT(ed.employee_day_position) AS count
FROM employee_days ed,
    days d
WHERE ed.employee_days_employee_id = '$employee_id'
    AND ed.employee_days_day_id = d.day_id
    AND d.day_year_id = '$year'
GROUP BY match_player_position
ORDER BY count DESC LIMIT 1

最后，我获得了一个平均权重，可以根据他们工作的日期和时间乘以销售额：

SELECT (SUM(dw.day_weighting_value)/COUNT(s.day_weighting_value)) AS employee_weigting
    FROM employee_days ed,
    day_weightings dw,
    days d
WHERE ed.employee_day_employee_id = '$employee_id'
    AND ed.employee_day_day_id = d.day_id
    AND d.day_year_id = '$year'
    AND dw.day_weighting_day_id = d.day_id
    AND dw.day_weighting_minute >= ed.employee_day_start_minute
    AND dw.day_weighting_minute <= ed.employee_day_end_minute`

任何人都可以向我提供有关这是否可行的指导，如果有的话，从哪里开始呢？

提前致谢！

Answer 1

第一个和第三个查询很容易加入。您只需编写一个子查询，该子查询返回为每个员工ID分组的结果，并将这些子查询连接到原始查询。

SELECT p.employee_id,
    e.employee_name,
    COUNT(s.sale_id) AS employee_sales,
    ed.employee_minutes,
    edw.employee_weighting
FROM employees e
JOIN sales s ON e.employee_id = s.sale_employee_id
JOIN days d ON s.sale_day_id = d.day_id
JOIN (SELECT ed.employee_days_employee_id, SUM(employee_day_end_minute-employee_day_start_minute) AS employee_minutes
      FROM employee_days ed
      JOIN days d ON ed.employee_days_day_id = d.day_id
      WHERE d.day_year_id = '$year'
      GROUP BY ed.employee_days_employee_id) AS ed ON ed.employee_days_employee_id = e.employee_id
JOIN (SELECT ed.employee_days_employee_id, (SUM(dw.day_weighting_value)/COUNT(s.day_weighting_value)) AS employee_weigting
      FROM employee_days ed
      JOIN day_weightings dw ON dw.day_weighting_minute >= ed.employee_day_start_minute
                                AND dw.day_weighting_minute <= ed.employee_day_end_minute
      days d ON dw.day_weighting_day_id = d.day_id
                AND ed.employee_day_day_id = d.day_id
      WHERE d.day_year_id = '$year'
      GROUP BY ed.employee_days_employee_id) AS edw ON edw.employee_days_employee_id = e.employee_id
WHERE s.sale_id = '$sale_type'
      AND d.day_year_id = '$year'
GROUP BY e.employee_id

中间查询更难。可能有一种方法可以将其写为单个查询，返回按员工分组的最高职位，但我现在无法想到它。

使用JOIN将三个MySQL查询合并为一个

1 个答案: