复合索引顺序MySQL查询

我正在尝试优化以下mysql查询。它运行约2.5秒。我已经读过关于复合索引的书，但我希望有人能帮助我理解如何使用这样的查询来排序复合索引，这些查询包含多个连接、许多where条件（包括日期范围）、group by和ORDER by（基于计算值）。我是否缺少一个有用的复合索引？是否有更有效的方法从这些表中提取数据？非常感谢您的帮助

SELECT 
branch.name AS branch,
SUM(appointment.status =  'completed') AS `Completed`, 
SUM(appointment.status =  'cancelled') AS `Cancelled`, 
SUM(appointment.status =  'not completed') AS `Not Completed`, 
SUM(appointment.status != 'rescheduled') AS `Total`
FROM rep
JOIN customer ON rep.id = customer.rep_id
JOIN office ON rep.office_id = office.id
JOIN appointment ON customer.id = appointment.customer_id
JOIN branch ON office.branch_id = branch.id
WHERE rep.active= 1 
AND rep.group IN (1,2,3) 
AND rep.deleted = 0 
AND customer.saved = 0 
AND (customer.rep_id != appointment.closed_by OR appointment.closed_by IS NULL)
AND customer.rep_id != 0 
AND customer.deleted = 0
AND office.visible = 1 
AND office.deleted = 0 
AND appointment.date >= '2016-12-01'
AND appointment.date < '2017-11-30' 
AND appointment.current = 1 
GROUP BY branch.id
ORDER BY Completed

建议

根据条件删除周围不可用的（）

  LEFT JOIN customer ON rep.id = customer.rep_id
  LEFT JOIN office ON rep.office_id = office.id
  LEFT JOIN appointment ON customer.id = appointment.customer_id
  LEFT JOIN branch ON office.branch_id = branch.id

---

在不了解任何数据的情况下，您的查询建议使用索引

office（已删除、可见、分支机构id）

。然而，这个表似乎只包含少数行，因此这个索引可能不会有多大帮助；要选择更好的策略，可以尝试识别强过滤器。例如，如果99%的数据将具有

customer.saved=1

或

约会.current！=1

，您可以尝试使用此选项优化查询，但这取决于您的数据。此外，为了清楚起见，您应该用

join

（如果

office.branch\u id

为

非空，则最后一个也应替换为
左join
）
  LEFT JOIN customer ON rep.id = customer.rep_id
  LEFT JOIN office ON rep.office_id = office.id
  LEFT JOIN appointment ON customer.id = appointment.customer_id
  LEFT JOIN branch ON office.branch_id = branch.id