0 运行 AI代码解释 CREATE TABLE example ( id INT(5)ZEROFILL, code INT(10) ZEROFILL ); INSERT INTO example VALUES (12, 12345); 查询结果会显示为: 代码语言:javascript代码运行次数0 运行 AI代码解释 +---+---+ | id | code| +---+---+ | 00012 | 0000012345 | +---+---+ MySQL...
CREATE TABLE example (id INT) ENGINE=InnoDB; MyISAM:适合读密集型应用,支持全文索引CREATE TABLE logs (id INT, message TEXT) ENGINE=MyISAM; Memory:将数据存储在内存中,速度极快但不持久CREATE TABLE temp_data (id INT) ENGINE=MEMORY; Archive:适合存储和检索大量很少被查询的历史数据...
mysql create table primary key auto_increment mysql> create table ss(id intunsignednot nullprimary key auto_increment, user_namevarchar(15)not null); Query OK, 0 rows affected (0.00 sec) mysql> mysql>insert into ss(id,user_name) values(1, 'jojo'); Query OK, 1 row affected (0.00 sec...
If you want to set particular columns of the table as the primary key, you use the following syntax: PRIMARY KEY (col1,col2,...) Example of MySQL CREATE TABLE statement Let’s practice with an example of creating a new table namedtasksin our sample database as follows: You can use t...
SET FOREIGN_KEY_CHECKS = 1; As mentioned, this is a bit of an obscure technique, combining this MySQL foreign keys check with the need to drop a database table and then re-create the table, while the table had very little data in it, but hey, if it helps anyone else, I'm happy...
CREATE TABLE city( cityid VARCHAR(32) PRIMARY KEY NOT NULL COMMENT '城市编号', cityname VARCHAR(32) NOT NULL COMMENT '城市名称' ) 1. 2. 3. 4. 2.2 初始化数据 插入的学生数据 -- 插入的学生数据 INSERT INTO student(sid, class, profession,NAME,phone,sex,cityid) VALUES('140513001','3'...
CREATE TABLE `testt` (`id` int(11) NOT NULL AUTO_INCREMENT,`userName` varchar(20) NOT NULL,`password` char(20) NOT NULL,PRIMARY KEY (`id`),UNIQUE KEY `id` (`id`),UNIQUE KEY `userName` (`userName`),UNIQUE KEY `password` (`userName`),UNIQUE KEY `userName_2` (`...
SELECT * FROM table where kid=1342 and type=1 order id asc limit 149420 ,20; 1. 2. 3. 4. 5. 该SQL是一个非常典型的排序+分页查询: order by col limit N,M MySQL 执行此类SQL时需要先扫描到N行,然后再去取M行。对于此类操作,获取前面少数几行数据会很快,但是随着扫描的记录数越多,SQL的性能...
CREATE TABLE stu_info (id INT PRIMARY KEY AUTO_INCREMENT name VARCHAR(20) NOT NULL age TINYINT genderENUM(’男’,’女’)create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP );这里id是自增主键，name限制20字符且不能为空，年龄用TINYINT节省空间，性别只允许填男或女，创建时间自动记录当前时间戳。
Re: Dba.createCluster: ERROR: 1 table(s) do not have a Primary Key or Primary Key Equivalent (non-null unique key) on sys.sys_config 1514 OpenSource DBA August 18, 2017 02:33AM Sorry, you can't reply to this topic. It has been closed....