Question

我写了一个复杂的查询，它最初检索了我想要的所有数据。现在我意识到我要求一个字段的值与我现在的值略有不同。

我有：IF(MIN(tasks.due_date) < NOW(),1,0) AS taskoverdue我想拥有它：

IF(MIN(tasks.due_date WHERE tasks.completed != 1) < NOW(),1,0) AS taskoverdue

我知道这种语法不起作用，是否有任何人可以想到会实现这种结果的操作？

由于我的查询很复杂，我不能改变where子句或group by子句，并且我不能在select子句中运行子查询而不会大大地破坏我的应用程序的速度。哦，我正在使用PHP，但我正在寻找一个mysql解决方案。

以下是我的完整查询，仅用于踢：

SELECT 
    tickets.id,
    tickets.user_id,
    tickets.name,
    COUNT(DISTINCT tasks.id) AS numTasks,
    IF(MIN(tasks.due_date) < NOW(),1,0) AS taskoverdue,
    IF(tickets.due_date < NOW(),1,0) AS ticketoverdue,
    tasks.queue_id AS queue_id ,
    IF(MIN(tasksteps.time_due) < NOW(),1,0) AS taskstepoverdue,
    COUNT(DISTINCT ticketnotes.ticket_id) as notes
FROM 
    tickets
    LEFT OUTER JOIN ticketsinqueues ON tickets.id = ticketsinqueues.ticket_id
    LEFT OUTER JOIN tasks ON tickets.id = tasks.ticket_id
    LEFT OUTER JOIN tasksteps ON tasks.id = tasksteps.task_id 
    LEFT OUTER JOIN ticketnotes ON tickets.id = ticketnotes.ticket_id
WHERE
    ticketsinqueues.queue_id != tasks.queue_id AND
    tickets.status = (var decided on run time)
GROUP BY
    tickets.id,tasks.queue_id
UNION
SELECT 
    tickets.id,
    tickets.user_id,
    tickets.name,
    COUNT(DISTINCT tasks.id) AS numTasks,
    IF(MIN(tasks.due_date) < NOW(),1,0) AS taskoverdue,
    IF(tickets.due_date < NOW(),1,0) AS ticketoverdue,
    tasks.queue_id AS queue_id ,
    IF(MIN(tasksteps.time_due) < NOW(),1,0) AS taskstepoverdue,
    COUNT(DISTINCT ticketnotes.ticket_id) as notes
FROM 
    tickets
    LEFT OUTER JOIN ticketsinqueues ON tickets.id = ticketsinqueues.ticket_id
    LEFT OUTER JOIN tasks ON tickets.id = tasks.ticket_id
    LEFT OUTER JOIN tasksteps ON tasks.id = tasksteps.task_id 
    LEFT OUTER JOIN ticketnotes ON tickets.id = ticketnotes.ticket_id
WHERE
    ticketsinqueues.queue_id = tasks.queue_id AND
    tickets.status = (var decided on run time)
GROUP BY
    tickets.id,tasks.queue_id
UNION
SELECT 
    tickets.id,
    tickets.user_id,
    tickets.name,
    0 AS numTasks,
    0 AS taskoverdue,
    IF(tickets.due_date < NOW(),1,0) AS ticketoverdue,
    ticketsinqueues.queue_id AS queue_id ,
    0 AS taskstepoverdue,
    0 AS notes
FROM 
    tickets 
    LEFT OUTER JOIN ticketsinqueues ON tickets.id = ticketsinqueues.ticket_id
WHERE 
tickets.status = (var decided on run time) AND
NOT EXISTS (
    SELECT 
        * 
    FROM 
        tasks 
    WHERE 
        tickets.id = tasks.ticket_id AND 
        tickets.queue_id = tasks.queue_id 
    GROUP BY 
        tasks.ticket_id,
        tasks.queue_id)
ORDER BY id desc

任何帮助将不胜感激。

Answer 1

MAX(tasks.completed != 1 AND tasks.due_date < NOW()) AS taskoverdue

只要另一个字段等于1，Mysql就会得到一个字段的最小值

1 个答案: