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qq_慕仔9098395
- 这和 where a.name=b.name 有啥区别呢是效率搞么
这个是条件
- 2021-11-01 1回答·883浏览
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慕标0505009
- over代表什么呢？
就是西游记中，人物结局的称号
- 2019-12-05 1回答·1028浏览
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橘色闪光0
- 两张 表的字段和数据可否提供
CREATE TABLE `user1` (
`id` int(11) NOT NULL COMMENT '主键',
`user_name` varchar(255) DEFAULT NULL COMMENT '姓名',
`over` varchar(255) DEFAULT NULL COMMENT '结局',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
INSERT INTO `blog`.`user1`(`id`, `user_name`, `over`) VALUES (1, '唐僧', '旃檀功德佛');
INSERT INTO `blog`.`user1`(`id`, `user_name`, `over`) VALUES (2, '猪八戒', '净坛使者');
INSERT INTO `blog`.`user1`(`id`, `user_name`, `over`) VALUES (3, '孙悟空', '斗战胜佛');
INSERT INTO `blog`.`user1`(`id`, `user_name`, `over`) VALUES (4, '沙僧', '金身罗汉');
CREATE TABLE `user2` (
`id` int(11) NOT NULL COMMENT '主键',
`user_name` varchar(255) DEFAULT NULL COMMENT '姓名',
`over` varchar(255) DEFAULT NULL COMMENT '结局',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
INSERT INTO `blog`.`user2`(`id`, `user_name`, `over`) VALUES (1, '孙悟空', '成佛');
INSERT INTO `blog`.`user2`(`id`, `user_name`, `over`) VALUES (2, '牛魔王', '被降服');
INSERT INTO `blog`.`user2`(`id`, `user_name`, `over`) VALUES (3, '蛟魔王', '被降服');
INSERT INTO `blog`.`user2`(`id`, `user_name`, `over`) VALUES (4, '鹏魔王', '被降服');
INSERT INTO `blog`.`user2`(`id`, `user_name`, `over`) VALUES (5, '狮驼王', '被降服');
- 2019-08-10 2回答·1006浏览
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柠檬的眼泪是酸的
- 西天取经四人组和悟空的朋友们数据表
打怪表在哪
- 2019-02-16 2回答·1710浏览
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故事还是关于你啊
- 数据表是啥啊
各位好，现提供该课程建库建表脚本共享，不过建议初学者最好依靠自己敲代码。
-- 注意自己是否需要建库 -- create database if not exists mysqldv1; -- 新建 user1 表 create table if not exists user1 ( id smallint unsigned primary key auto_increment, user_name varchar(40), over varchar(40) ); -- 新建 user2 表 create table if not exists user2 ( id smallint unsigned primary key auto_increment, user_name varchar(40), over varchar(40) ); -- 新建 user_kills 表 create table if not exists user_kills ( id smallint unsigned primary key auto_increment, user_id smallint unsigned, timestr timestamp default CURRENT_TIMESTAMP, kills smallint unsigned ); -- 插入 user1 表数据 insert into user1(user_name,over) values ('唐僧', '旃檀功德佛'); insert into user1(user_name,over) values ('猪八戒', '净坛使者'); insert into user1(user_name,over) values ('孙悟空', '斗战胜佛'); insert into user1(user_name,over) values ('沙僧', '金身罗汉'); -- 插入 user2 表数据 insert into user2(user_name,over) values ('孙悟空', '成佛'); insert into user2(user_name,over) values ('牛魔王', '被降服'); insert into user2(user_name,over) values ('蛟魔王', '被降服'); insert into user2(user_name,over) values ('鹏魔王', '被降服'); insert into user2(user_name,over) values ('狮驼王', '被降服'); -- 插入 user_kills 表数据 insert into user_kills(user_id, timestr, kills) values (2, timestamp('2013-01-10'), 10); insert into user_kills(user_id, timestr, kills) values (2, timestamp('2013-02-01'), 2); insert into user_kills(user_id, timestr, kills) values (2, timestamp('2013-02-05'), 12); insert into user_kills(user_id, timestr, kills) values (4, timestamp('2013-01-10'), 3); insert into user_kills(user_id, timestr, kills) values (4, timestamp('2013-02-11'), 5); insert into user_kills(user_id, timestr, kills) values (2, timestamp('2013-02-06'), 1); insert into user_kills(user_id, timestr, kills) values (3, timestamp('2013-01-11'), 20); insert into user_kills(user_id, timestr, kills) values (2, timestamp('2013-02-12'), 10); insert into user_kills(user_id, timestr, kills) values (3, timestamp('2013-02-07'), 17);- 2017-02-08 2回答·2025浏览
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Promises
- 求解答求解答
user1 user2 是表明 a,b 是别名 为了在sql中区别
- 2016-05-10 1回答·540浏览
