MySQL的简单实用 手把手教学
MySQL的使用
1.登陆数据库
打开terminal
在终端根文件目录下输入/usr/local/mysql/bin/mysql -u root -p
接着输入管理员密码
2.显示所有的数据库
输入:
mysql> SHOW DATABASES;
(不要忘记加 ‘ ; ’ ,在mysql中分号为一句语句的结束)
显示结果:
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| studb |
| sys |
+--------------------+
5 rows in set (0.06 sec)
3.使用数据库
在上面的显示的数据库中,使用studb
数据库,输入:
mysql> USE studb;
若没有创建过数据库,则可以使用以下命令来创建数据库:
mysql> CREATE DATABASE studb;
4.展示数据库中所有的表
输入:
mysql> SHOW TABLES;
显示结果:
+-----------------+
| Tables_in_studb |
+-----------------+
| student |
+-----------------+
1 row in set (0.00 sec)
可以看到数据库有一张表,若没有创建表,则可以使用下面的命令创建:
mysql> CREATE TABLE student(
->stu_id INT PRIMARY KEY NOT NULL,
->stu_name CHAR(25) NOT NULL,
->stu_email CHAR(25) NULL,
->stu_address CHAR(50) NULL);
5.打印表的结构
输入:
mysql> DESC student;
显示结果:
+-------------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+----------+------+-----+---------+-------+
| stu_id | int | NO | PRI | NULL | |
| stu_name | char(25) | NO | | NULL | |
| stu_email | char(25) | YES | | NULL | |
| stu_address | char(50) | YES | | NULL | |
+-------------+----------+------+-----+---------+-------+
4 rows in set (0.00 sec)
6.向表中插入数据
输入:
mysql> INSERT INTO student(stu_id, stu_name, stu_email, stu_address)
-> VALUES(2020100116,'张三','zhangsan@163.com','beijin');
7.查看表中数据
输入:
mysql> SELECT *
-> FROM student;
显示结果:
+------------+----------+------------------+-------------+
| stu_id | stu_name | stu_email | stu_address |
+------------+----------+------------------+-------------+
| 2020100116 | 张三 | zhangsan@163.com | beijin |
+------------+----------+------------------+-------------+
1 row in set (0.00 sec)
8.修改表中的数据
输入:
mysql> UPDATE student
-> SET stu_email = 'nbplus@qq.com'
-> WHERE stu_id = 2020100116;
更新成功后,查看更新结果:
mysql> SELECT stu_id, stu_name, stu_email
-> FROM student
-> WHERE stu_id = 2020100116;
显示结果:
+------------+----------+---------------+
| stu_id | stu_name | stu_email |
+------------+----------+---------------+
| 2020100116 | 张三 | nbplus@qq.com |
+------------+----------+---------------+
1 row in set (0.00 sec)
9.删除表中的数据
输入:
mysql> DELETE FROM student WHERE stu_id = 2020100116;
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