WebCREATE TABLE test ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY ); INSERT INTO test VALUES (NULL); SELECT * FROM test; Result: id 1 mysql primary-key auto-increment notnull Share Improve this question Follow asked Oct 5, 2015 at 20:04 Grzegorz Adam Kowalski 5,127 3 30 39 Add a comment 1 Answer Sorted by: 3 Well, as seen in … Web1. Why NOT NULL in column definition does not work if that column has both PRIMARY KEY and AUTO_INCREMENT? Tested on MySQL 5.6. CREATE TABLE test ( id INT …
MySQL表添加AUTO_INCREMENT列或者把现有的表字段设置 …
WebTo create a PRIMARY KEY constraint on the "ID" column when the table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Persons ADD PRIMARY KEY (ID); To allow naming of a PRIMARY KEY constraint, and for defining a PRIMARY KEY constraint on multiple columns, use the following SQL … Webid int auto_increment comment '主键' primary key, category_id int null comment '种类id', image_url varchar(100) null comment '图片地址'); create table if not exists tb_post (id int auto_increment comment '主键' primary key, campus int null comment '0北洋园1卫津路', category_id int null comment '种类id', stewart beall macnichols \u0026 harmell
NOT NULL not working on primary key with auto increment
Web16 uur geleden · PRIMARY KEY (`id`) ) ENGINE = InnoDB AUTO_INCREMENT =4 DEFAULT CHARSET = utf8 COMMENT ='配置文件'; -- ---------------------------- -- Table structure for dictionary -- ---------------------------- DROP TABLE IF EXISTS `dictionary`; CREATE TABLE `dictionary` ( `id` bigint ( 20) NOT NULL AUTO_INCREMENT … Web16 nov. 2011 · id int primary key auto _ increment 是 什么意思 这是一句Mysql语句 id 表示属性名 int 表示属性类型 primary key 表示这个属性是主键 auto _ increment de表示这个值是自动增加的, 默认开始值是1,如果希望修改起始值,格式如下: alter table cin_01 auto _ increment = 20; ... Mysql日期函数 Web1、创建一个自增主键的表 create table t_user( `id` INT NOT NULL AUTO_INCREMENT COMMENT '主键id', `age` INT(11) NOT NULL DEFAULT 10 COMMENT '年龄', PRIMARY KEY (`id`) ) 2、SQL插入数据时的写法. insert into t_user(age) values(18) insert into t_user(age) values(20) 查询一下上述的插入数据 stewart beauty