4、数据的基本操作

1.插入数据；对指定的列插入数据；
推荐：就记这一种；因为不加字段的容易插入错误；
INSERT INTO 表名（字段名1，字段名2) VALUE(值1，值2);
1-1向mitseek插入数据

mysql> INSERT INTO mitseek(
    -> id,name,age) VALUE(
    -> 1,'name1',23
    -> );

2，批量插入数据
INSERT INTO 表名（字段名1，字段名2) VALUE(值1，值2),(值1，值2);
1-2向mitseek插入2行数据；

mysql> INSERT INTO  mitseek(
    -> id,name,age) value(
    -> 2,'name2',24),(3,'name3',22
    -> );
Query OK, 2 rows affected (0.02 sec)
Records: 2  Duplicates: 0  Warnings: 0

1-2-1查看所添加的数据

mysql> SELECT  * FROM mitseek;
+------+-------+------+
| id   | name  | age  |
+------+-------+------+
|    1 | name1 |   23 |
|    2 | name2 |   24 |
|    3 | name3 |   22 |
+------+-------+------+

3 rows in set (0.00 sec)
3、更新数据
UPDATE 表名
SET 字段名1=值1 [,字段名2=值2]
[WHERE 条件表达式]；
3-1修改mitseek表中id为2的数据，名字改为name2_1

mysql> UPDATE mitseek
    -> SET name='name_2'
    -> WHERE id=2;
Query OK, 1 row affected (0.03 sec)
Rows matched: 1  Changed: 1  Warnings: 0
mysql> SELECT * FROM mitseek;
+------+--------+------+
| id   | name   | age  |
+------+--------+------+
|    1 | name1  |   23 |
|    2 | name_2 |   24 |
|    3 | name3  |   22 |
+------+--------+------+
3 rows in set (0.00 sec)

4、删除数据
DELETE FROM 表名 [WHERE 条件表达式]；
4-1删除部分数据
4-1-1删除mitseek表中的name3

mysql> SELECT * FROM mitseek;
+------+--------+------+
| id   | name   | age  |
+------+--------+------+
|    1 | name1  |   23 |
|    2 | name_2 |   24 |
|    3 | name3  |   22 |
+------+--------+------+
3 rows in set (0.00 sec)

mysql> DELETE FROM mitseek WHERE name='name3';
Query OK, 1 row affected (0.03 sec)

mysql> SELECT * FROM mitseek;
+------+--------+------+
| id   | name   | age  |
+------+--------+------+
|    1 | name1  |   23 |
|    2 | name_2 |   24 |
+------+--------+------+
2 rows in set (0.00 sec)

4-2删除全部数据

mysql> DELETE FROM mitseek;
Query OK, 2 rows affected (0.03 sec)

mysql> SELECT * FROM mitseek;
Empty set (0.00 sec)

mysql> DESC mitseek;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| name  | varchar(10) | YES  |     | NULL    |       |
| age   | int(10)     | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)