mySQL条件选择?

时间:2017-01-28 12:33:33

标签: mysql sql

表:idstatustime

$now = time(); // current timestamp

$statuses = array (
    'ST1' => 60,  // (seconds)
    'ST2' => 120,  // (seconds)
    'ST3' => 180,  // (seconds)
);

$query = 'SELECT id FROM table WHERE status IN("ST1", "ST2", "ST3") AND time ... LIMIT 1';

现在,我想从表格中选择id 1 row

如果status是ST1 :(时间+60)>现在$

如果status是ST2 :(时间+ 120)>现在$

如果status是ST3 :(时间+ 180)>现在$

因此,如果该行具有列status =“ST1”,则它会检查列time + 60是否大于$now这是当前时间戳,依此类推。

2 个答案:

答案 0 :(得分:3)

只需使用基本逻辑:

SELECT l.id
FROM leads l 
WHERE ((l.status = 'ST1' and l.time > date_sub(now(), interval 60 second)) or
       (l.status = 'ST2' and l.time > date_sub(now(), interval 120 second)) or
       (l.status = 'ST3' and l.time > date_sub(now(), interval 180 second)) 
      )
LIMIT 1;

我假设(time + xx) > $now指的是秒。此外,我鼓励您使用数据库时间,而不是传入它。(当然,您可以将now()替换为$now - 或者更好的参数 - 如果您有充分的理由从申请中抽出时间。)

老实说,我可能会把它放在派生表中:

SELECT l.id
FROM leads l JOIN
     (SELECT 'ST1' as status, 60 as diff UNION ALL
      SELECT 'ST2' as status, 120 as diff UNION ALL
      SELECT 'ST3' as status, 180 as diff
     ) s
     ON l.status = s.status
WHERE l.time > date_sub(now(), interval s.diff second)
LIMIT 1;

答案 1 :(得分:2)

使用CASE声明:

SELECT id FROM table WHERE 
CASE 
    WHEN status="ST1" THEN (time + INTERVAL 60 SECOND) > NOW() 
    WHEN status="ST2" THEN (time + INTERVAL 120 SECOND) > NOW() 
    WHEN status="ST3" THEN (time + INTERVAL 180 SECOND) > NOW() 
END CASE
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