的MySQL则返回0查询为空

此查询应该选择一些统计值形成一个表：的MySQL则返回0查询为空

(SELECT MAX(`id`) as `count` FROM `stats` LIMIT 1) 
UNION (SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 1 DAY) LIMIT 1) 
UNION (SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 7 DAY) LIMIT 1) 
UNION (SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 30 DAY) LIMIT 1) 
UNION (SELECT DATE_FORMAT(MIN(`time`), '%D of %M, %Y') as `count` FROM `stats` LIMIT 1)

我尝试这样做，但它不工作

(SELECT MAX(`id`) as `count` FROM `stats` LIMIT 1) 
UNION IFNULL((SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 1 DAY) LIMIT 1), '0') 
UNION IFNULL((SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 7 DAY) LIMIT 1), '0') 
UNION IFNULL((SELECT COUNT(*) as `count` FROM `stats` WHERE DATE(`time`) >= (NOW() - INTERVAL 30 DAY) LIMIT 1), '0') 
UNION IFNULL((SELECT DATE_FORMAT(MIN(`time`), '%D of %M, %Y') as `count` FROM `stats` LIMIT 1), '0')

来源

2016-02-10 Display Name

什么意思dosen't工作..错误。？错误的结果？ .. – scaisEdge

它返回一个错误，'＃1064 - 你的SQL语法有错误;检查与您的MySQL服务器版本相对应的手册，以便在'IFNULL（（SELECT COUNT（*）'作为\'count \'FROM \'stats \''WHERE DATE（\'time \'）> = NOW（） - 我在第2行' –

你要做SELECT在IFNULL：

SELECT MAX(`id`) as `count` FROM `stats` LIMIT 1 
UNION 
SELECT IFNULL((SELECT COUNT(*) as `count` 
       FROM `stats` 
       WHERE DATE(`time`) >= (NOW() - INTERVAL 1 DAY) LIMIT 1), 0) 
UNION 
SELECT IFNULL((SELECT COUNT(*) as `count` 
       FROM `stats` 
       WHERE DATE(`time`) >= (NOW() - INTERVAL 7 DAY) LIMIT 1), 0) 
UNION 
SELECT IFNULL((SELECT COUNT(*) as `count` 
       FROM `stats` 
       WHERE DATE(`time`) >= (NOW() - INTERVAL 30 DAY) LIMIT 1), 0) 
UNION 
SELECT IFNULL((SELECT DATE_FORMAT(MIN(`time`), '%D of %M, %Y') as `count` 
       FROM `stats` LIMIT 1), 0)

您还可以使用0，而不是 '0'，并得到摆脱围绕第一个查询的括号。

来源

2016-02-10 18:29:29

这非常有帮助，非常感谢！ –

的MySQL则返回0查询为空

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