mysql基础 primary key auto_increment 创建主键、自增长的字段

原创云散月明 All China Database Union 2021-04-29

686

OS : Ubuntu 18.04.1 LTS
DBMS : mysql 8.0.12

示例

stu@Ubuntu:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 25
Server version: 8.0.12 MySQL Community Server - GPL

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Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use db_chinese_medicine;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> create table `t_primary_auto_test`(
    -> `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键,自增长',           
    -> PRIMARY KEY (`id`)                                                           
    -> )                                                                            
    -> ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='测试表';                                                                       
Query OK, 0 rows affected (0.10 sec)

mysql> desc t_primary_auto_test;
+-------+------------------+------+-----+---------+----------------+
| Field | Type             | Null | Key | Default | Extra          |
+-------+------------------+------+-----+---------+----------------+
| id    | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
+-------+------------------+------+-----+---------+----------------+
1 row in set (0.01 sec)

mysql> exit
Bye
stu@Ubuntu:~$