1.插入数据 insert into 表名 values("字段1“，字段2.)
mysql> insert into classes values(null,"WuLiu",98);
Query OK, 1 row affected (0.01 sec)
多行插入
mysql> insert into classes values(3,"GuanLi",22),(4,"KuaiJi",55);
Query OK, 2 rows affected (0.00 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> desc classes;
+-------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| name | varchar(10) | YES | | NULL | |
| num | int(11) | YES | | NULL | |
+-------+------------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
mysql> select * from classes;
+----+-----------+------+
| id | name | num |
+----+-----------+------+
| 1 | DianShang | 48 |
| 2 | WuLiu | 98 |
| 3 | GuanLi | 22 |
| 4 | KuaiJi | 55 |
+----+-----------+------+
4 rows in set (0.00 sec)
2.查询数据
mysql> select * from classes;
+----+-----------+------+
| id | name | num |
+----+-----------+------+
| 1 | DianShang | 48 |
| 2 | WuLiu | 98 |
+----+-----------+------+
2 rows in set (0.00 sec)
mysql> insert into students(id,name,age,gender) values(null,'xiaobao',25,'man');
Query OK, 1 row affected (0.00 sec)
mysql> select * from students;
+----+---------+------+------+--------+--------+
| id | name | age | high | gender | cls_id |
+----+---------+------+------+--------+--------+
| 1 | dabao | NULL | NULL | NULL | NULL |
| 2 | xiaobao | 25 | NULL | man | NULL |
+----+---------+------+------+--------+--------+
2 rows in set (0.00 sec)
3.update 表 set 字段名=值”where 条件；
mysql> update students set age=56 where name='dabao';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from students;
+----+---------+------+------+--------+--------+
| id | name | age | high | gender | cls_id |
+----+---------+------+------+--------+--------+
| 1 | dabao | 56 | NULL | NULL | NULL |
| 2 | xiaobao | 25 | NULL | man | NULL |
+----+---------+------+------+--------+--------+
2 rows in set (0.00 sec)
4.delete from 表名字 where条件;
delete from students where id=2;
mysql> delete from classes where id=2;
Query OK, 1 row affected (0.00 sec)
数据库备份：
mysqldump -uroot -p school_data > school_data1.sql
