MySQL从小白到总裁完整教程目录:https://blog.csdn.net/weixin_67859959/article/details/129334507?spm=1001.2014.3001.5502

语法格式:

desc 表名;

描述:

如果表不存在,就提示不存在;

如果表存在,就显示表的结构

比如:

desc test01;

desc test02;

错误示范:

mysql> desc 666;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '666' at line 1

有的可能因为版本的不同,报错的原因有所区别,但是问题不大

正确的:

mysql> desc test01;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| name  | varchar(30) | YES  |     | NULL    |       |
| age   | int(11)     | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.03 sec)

mysql> desc test02;
+--------+-------------+------+-----+---------+-------+
| Field  | Type        | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| id     | int(8)      | YES  |     | NULL    |       |
| name   | varchar(30) | YES  |     | NULL    |       |
| gender | char(3)     | YES  |     | NULL    |       |
| score  | double(4,1) | YES  |     | NULL    |       |
+--------+-------------+------+-----+---------+-------+
4 rows in set (0.03 sec)

两个表还是不够用,再来创建一个表吧

create table test03(name     varchar(30),   #姓名age      int(3),        #年龄salary   double(8,2),   #工资etime    date,          #入职日期address  varchar(50)    #地址
);

 为下次做准备

练习:创建一张表，表名为work01，表中包含的字段有：

       wid       int
   wname     varchar(30)
   gender     char(3)
   score       double(4,1)
   wtime      date
 address    varchar(50)

create table work01(wid      int,wname    varchar(30),gender   char(3),score    double(4,1),wtime    date,address  varchar(50)
);