從多個表中選擇，但按日期時間字段排序

Question

我有3個不相關的表（每個表都包含不同社交網絡的數據）。每個人都有一個時間字段dated-我已經按小時分組，你可以看到低於（這一個linked_in）

SELECT count(*), date_format(dated, '%Y:%m:%d %H') as hour 
FROM upd8r_linked_in_accts 
WHERE CAST(dated AS DATE) = '".$start_date."' 
GROUP BY hour 

我想知道如何在所有3個網絡 - 表共做爲三個是

CREATE TABLE IF NOT EXISTS `upd8r_facebook_accts` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `owner_id` varchar(50) NOT NULL, 
    `user_id` int(11) NOT NULL, 
    `fb_id` bigint(30) NOT NULL, 
    `dated` datetime NOT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=80 ; 

CREATE TABLE IF NOT EXISTS `upd8r_linked_in_accts` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `owner_id` varchar(50) NOT NULL, 
    `user_id` int(11) NOT NULL, 
    `linked_in` varchar(200) NOT NULL, 
    `oauth_secret` varchar(100) NOT NULL, 
    `first_count` int(11) NOT NULL, 
    `second_count` int(11) NOT NULL, 
    `dated` datetime NOT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=200 ; 

CREATE TABLE IF NOT EXISTS `upd8r_twitter_accts` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `owner_id` varchar(50) NOT NULL, 
    `user_id` int(11) NOT NULL, 
    `twitter` varchar(200) NOT NULL, 
    `twitter_secret` varchar(100) NOT NULL, 
    `dated` datetime NOT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=9 ; 

這樣的事情？

(SELECT count(*), date_format(dated, '%Y:%m:%d %H') as hour 
FROM upd8r_linked_in_accts 
WHERE CAST(dated AS DATE) = '".$start_date."') 
UNION ALL 
(SELECT count(*), date_format(dated, '%Y:%m:%d %H') as hour 
FROM upd8r_facebook_accts 
WHERE CAST(dated AS DATE) = '".$start_date."') 
UNION ALL 
(SELECT count(*), date_format(dated, '%Y:%m:%d %H') as hour 
FROM upd8r_twitter_accts 
WHERE CAST(dated AS DATE) = '".$start_date."') 
UNION ALL 
GROUP BY hour 

更新

在實際的數據庫中的數據不被任何PK或FK相關但數據與每個表代表一個用戶通過應用程序註冊用於社交網絡，因此我需要向用戶展示每小時註冊量在所有三個表

更新2

輸出Ø f查詢應該顯示％Y：％m：％d％H以及三個表格每小時的註冊用戶數量（創建的記錄）。每小時返回一個新行（按時間排序）

Answer 1

您接近解決方案

select t1.hourx, sum(t1.column1) 
from (
    (
    SELECT count(*) as column1, date_format(dated, '%Y:%m:%d %H') as hourx 
    FROM upd8r_linked_in_accts 
    WHERE CAST(dated AS DATE) = '".$start_date."' 
    GROUP BY hourx 
) 
    UNION ALL 
    (
    SELECT count(*) as column1, date_format(dated, '%Y:%m:%d %H') as hourx 
    FROM upd8r_facebook_accts 
    WHERE CAST(dated AS DATE) = '".$start_date."' 
    GROUP BY hourx 
) 
    UNION ALL 
    (
    SELECT count(*) as column1, date_format(dated, '%Y:%m:%d %H') as hourx 
    FROM upd8r_twitter_accts 
    WHERE CAST(dated AS DATE) = '".$start_date."' 
    GROUP BY hourx 
) 
) t1 
GROUP BY t1.hourx 

我使用'小時'來避免保留字，也許沒有必要。

我希望這可以工作。

[ADD]此解決方案被稱爲'內聯視圖'。你可以谷歌的。這是大多數的數據庫（MySQL和甲骨文MSSQL和等）