Mysql跨數據庫外鍵

Question

我想創建一個跨數據庫外鍵。當我在同一個數據庫上運行下面的代碼

CREATE TABLE `t1` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `int_id` varchar(128) COLLATE utf8_unicode_ci NOT NULL, 
    PRIMARY KEY (`id`), 
    UNIQUE KEY `int_id` (`int_id`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

CREATE TABLE `t2` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `ext_id` varchar(128) COLLATE utf8_unicode_ci NOT NULL, 
    PRIMARY KEY (`id`), 
    KEY `ext_id` (`ext_id`), 
    CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`ext_id`) REFERENCES `t1` (`int_id`) ON DELETE CASCADE 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

但是，當一個DATABSE（D1）創建T1，然後運行在第二DATABSE（D2）下面的代碼，我收到的一般錯誤：＃ 1005 - 無法創建表 'userdata.t2'（錯誤：150）

CREATE TABLE `t2` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `ext_id` varchar(128) COLLATE utf8_unicode_ci NOT NULL, 
    PRIMARY KEY (`id`), 
    KEY `ext_id` (`ext_id`), 
    CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`ext_id`) REFERENCES `d1.t1` (`int_id`) ON DELETE CASCADE 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

任何幫助將不勝感激。謝謝！

Answer 1

你的語法是不正確的，試試這個

CREATE TABLE `t2` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `ext_id` varchar(128) COLLATE utf8_unicode_ci NOT NULL, 
    PRIMARY KEY (`id`), 
    KEY `ext_id` (`ext_id`), 
    CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`ext_id`) REFERENCES `d1`.`t1` (`int_id`) ON DELETE CASCADE 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;