MYSQL-无法计算字段之间的时间差并且无法使用 where 子句

Question

这是计算 DateTimeSolved 和 DateTimeCreated 之间时差的 SQL 查询，我需要结果以小时为单位。

$query = "SELECT problem.id, problem.DateTimeCreated, problem.DateTimeSolved TIMEDIFF(HOUR, problem.DateTimeSolved, problem.DateTimeCreated)
From problem";

我在查询中添加了一个 where 子句:

$query = "SELECT problem.status, problem.id, problem.DateTimeSolved, problem.DateTimeCreated, TIMESTAMPDIFF(DAY, problem.DateTimeSolved, problem.DateTimeCreated) 从问题 WHERE problem.status = '5' GROUP BY MONTH(problem.DateTimeCreated) = MONTH(CURDATE())"; 这是查询的当前格式，但我得到的输出是负数。

当我尝试运行语句时仍然出现此错误:

You have an error in your SQL syntax;

check the manual that corresponds to your MySQL server version for the right syntax

Answer 1

错误信息是由于在 TIMEDIFF 函数前缺少一个逗号:

SELECT problem.id, problem.DateTimeCreated, problem.DateTimeSolved, TIMEDIFF(HOUR, problem.DateTimeSolved, problem.DateTimeCreated)

来自问题

然后你会发现你的TIMEDIFF参数不对。这应该有效:

SELECT problem.id, problem.DateTimeCreated, problem.DateTimeSolved, TIMEDIFF( problem.DateTimeSolved, problem.DateTimeCreated)
From problem

如果您只需要时间:

SELECT problem.id, problem.DateTimeCreated, problem.DateTimeSolved, HOUR(TIMEDIFF( problem.DateTimeSolved, problem.DateTimeCreated)) From problem