具有内部联接的 SQL 复杂查询以及介于两者之间的位置

Question

我无法理解为什么我的查询不起作用，而且我已经搜索了现有的主题。 我的目标 我正在尝试从我的 MySQL 中显示选定时间段内排名前 5 位的投诉类型。

预期结果 一个 5 行的表格，第一列显示 COUNT，第二列显示我的 Ticket Type 的描述

我正在使用的查询返回错误

SELECT
  COUNT(t.ticketType) AS total_amount, 
  tt.typeTekst AS description
  FROM Ticket t
  WHERE t.ticketStartTime BETWEEN 1612443540 AND 1613393340
  INNER JOIN TicketType tt ON t.ticketType = tt.typeId
  GROUP BY description
  ORDER BY total_amount desc
  LIMIT 5

类似查询有效，但不符合我的期望

没有正确的工单描述的表格

SELECT
  COUNT(t.ticketType) AS total_amount, 
  t.ticketType AS description
  FROM Ticket t
  WHERE t.ticketStartTime BETWEEN 1612443540 AND 1613393340
  GROUP BY description
  ORDER BY total_amount desc
  LIMIT 5

total_amount	description
4	7
3	6
2	10
2	5
1	30

表格没有选定的时间段，但有说明

SELECT
  COUNT(t.ticketType) AS total_amount,
  tt.typeDescription AS description
  FROM Ticket t
  INNER JOIN TicketType AS tt ON t.ticketType = tt.typeId 
  GROUP BY description
  ORDER BY total_amount desc
  LIMIT 5

total_amount	description
31	TicketType Placeholder A
10	TicketType Placeholder B
8	TicketType Placeholder C
5	TicketType Placeholder D
4	TicketType Placeholder E

感谢您的宝贵时间！

Answer 1

在加入所有表后使用 where 子句。请尝试以下查询：

SELECT
  COUNT(t.ticketType) AS total_amount, 
  tt.typeTekst AS description
  FROM Ticket t
  INNER JOIN TicketType tt ON t.ticketType = tt.typeId
  WHERE t.ticketStartTime BETWEEN 1612443540 AND 1613393340
  GROUP BY description
  ORDER BY total_amount desc
  LIMIT 5