的MySQL則返回0查詢爲空

此查詢應該選擇一些統計值形成一個表：的MySQL則返回0查詢爲空

(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)

我嘗試這樣做，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')

來源

2016-02-10 Display Name

什麼意思dosen't工作..錯誤。？錯誤的結果？ .. – scaisEdge

它返回一個錯誤，'＃1064 - 你的SQL語法有錯誤;檢查與您的MySQL服務器版本相對應的手冊，以便在'IFNULL（（SELECT COUNT（*）'作爲\'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)

您還可以使用0，而不是 '0'，並得到擺脫圍繞第一個查詢的括號。

來源

2016-02-10 18:29:29

這非常有幫助，非常感謝！ –

的MySQL則返回0查詢爲空

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