MySQL表操作

1.介绍

　　表就相当于文件，表中的一条记录就相当与文件的一行内容，不同的是，表中的一条记录有对应的标题，成为表的字段。

2.创建表

2.1语法

create table 表名(

字段名1 类型[(宽度) 约束条件],

字段名2 类型[(宽度) 约束条件],

字段名3 类型[(宽度) 约束条件],

);

注意：

    1. 必须进入数据库中才能创建表
    2. 标点符号均为英文标点符号

    3. 在同一张表中，字段名是不能相同的

    4. 宽度和约束条件为可选项

    5. 字段名和类型是必须的

2.2范例

1-使用默认格式创建表

mysql> use python25;

Database changed

mysql> show tables;

Empty set (0.00 sec)

mysql> create table test1(id int,

    -> name char(11),

    -> sex enum('male', 'female'),

    -> hobby set('swiming', 'running', 'basketball'));

Query OK, 0 rows affected (0.02 sec)

mysql> desc test1;

+-------+---------------------------------------+------+-----+---------+-------+

| Field | Type                                  | Null | Key | Default | Extra |

+-------+---------------------------------------+------+-----+---------+-------+

| id    | int(11)                               | YES  |     | NULL    |       |

| name  | char(11)                              | YES  |     | NULL    |       |

| sex   | enum('male','female')                 | YES  |     | NULL    |       |

| hobby | set('swiming','running','basketball') | YES  |     | NULL    |       |

+-------+---------------------------------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

2-自定义格式创建表

# 指定字符编码

mysql> create table test3 (

    -> id int,

    -> name char(10),

    -> age int,

    -> sex enum('male', 'female'),

    -> phone char(11),

    -> job char(10)

    -> ) charset=utf8;

Query OK, 0 rows affected (0.03 sec)

#指定存储引擎

mysql> create table test4 (

    -> id int,

    -> name char(10),

    -> age int,

    -> sex enum('male', 'female'),

    -> phone char(11),

    -> job char(10)

    -> ) ENGINE=MyISAM;

Query OK, 0 rows affected (0.01 sec)

3-查看表结构、创建表的语句

# 查看表结构

mysql> show columns from test1;

+-------+---------------------------------------+------+-----+---------+-------+

| Field | Type                                  | Null | Key | Default | Extra |

+-------+---------------------------------------+------+-----+---------+-------+

| id    | int(11)                               | YES  |     | NULL    |       |

| name  | char(11)                              | YES  |     | NULL    |       |

| sex   | enum('male','female')                 | YES  |     | NULL    |       |

| hobby | set('swiming','running','basketball') | YES  |     | NULL    |       |

+-------+---------------------------------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

mysql> desc test1;

+-------+---------------------------------------+------+-----+---------+-------+

| Field | Type                                  | Null | Key | Default | Extra |

+-------+---------------------------------------+------+-----+---------+-------+

| id    | int(11)                               | YES  |     | NULL    |       |

| name  | char(11)                              | YES  |     | NULL    |       |

| sex   | enum('male','female')                 | YES  |     | NULL    |       |

| hobby | set('swiming','running','basketball') | YES  |     | NULL    |       |

+-------+---------------------------------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

# 查看创建表的语句

mysql> show create table test1 \G;

*************************** 1. row ***************************

       Table: test1

Create Table: CREATE TABLE `test1` (

  `id` int(11) DEFAULT NULL,

  `name` char(11) DEFAULT NULL,

  `sex` enum('male','female') DEFAULT NULL,

  `hobby` set('swiming','running','basketball') DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=utf8

1 row in set (0.00 sec)

2.删除表

语法:

DROP TABLE 表名;

注意：删表要谨慎

mysql> show tables;

+--------------------+

| Tables_in_python25 |

+--------------------+

| test1              |

| test2              |

| test3              |

| test4              |

+--------------------+

4 rows in set (0.00 sec)

mysql> drop table test1;

Query OK, 0 rows affected (0.01 sec)

mysql> drop table test2;

Query OK, 0 rows affected (0.01 sec)

mysql> show tables;

+--------------------+

| Tables_in_python25 |

+--------------------+

| test3              |

| test4              |

+--------------------+

2 rows in set (0.00 sec)

3.修改表

3.1 修改表名

语法

ALTER TABLE 表名 RENAME 新表名;

范例

mysql> show tables;

+--------------------+

| Tables_in_python25 |

+--------------------+

| test3              |

| test4              |

+--------------------+

2 rows in set (0.00 sec)

mysql> alter table test3 rename test1;

Query OK, 0 rows affected (0.02 sec)

mysql> show tables;

+--------------------+

| Tables_in_python25 |

+--------------------+

| test1              |

| test4              |

+--------------------+

2 rows in set (0.00 sec)

3.2 增加字段

语法

ALTER TABLE 表名 ADD 字段名数据类型[(宽度) 约束条件], ADD 字段名数据类型[(宽度) 约束条件];

范例

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(10)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.01 sec)

# 增加hobby、home两个字段

mysql> alter table test1 add hobby set('football', 'running'), add home char(10);

Query OK, 0 rows affected (0.04 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+---------------------------+------+-----+---------+-------+

| Field | Type                      | Null | Key | Default | Extra |

+-------+---------------------------+------+-----+---------+-------+

| id    | int(11)                   | YES  |     | NULL    |       |

| name  | char(10)                  | YES  |     | NULL    |       |

| age   | int(11)                   | YES  |     | NULL    |       |

| sex   | enum('male','female')     | YES  |     | NULL    |       |

| phone | char(11)                  | YES  |     | NULL    |       |

| job   | char(10)                  | YES  |     | NULL    |       |

| hobby | set('football','running') | YES  |     | NULL    |       |

| home  | char(10)                  | YES  |     | NULL    |       |

+-------+---------------------------+------+-----+---------+-------+

8 rows in set (0.00 sec)

3.3 删除字段

语法

ALTER TABLE 表名 DROP 字段名;

范例

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(10)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.01 sec)

# 删除hobby、home字段

mysql> alter table test1 add hobby set('football', 'running'), add home char(10);

Query OK, 0 rows affected (0.04 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+---------------------------+------+-----+---------+-------+

| Field | Type                      | Null | Key | Default | Extra |

+-------+---------------------------+------+-----+---------+-------+

| id    | int(11)                   | YES  |     | NULL    |       |

| name  | char(10)                  | YES  |     | NULL    |       |

| age   | int(11)                   | YES  |     | NULL    |       |

| sex   | enum('male','female')     | YES  |     | NULL    |       |

| phone | char(11)                  | YES  |     | NULL    |       |

| job   | char(10)                  | YES  |     | NULL    |       |

| hobby | set('football','running') | YES  |     | NULL    |       |

| home  | char(10)                  | YES  |     | NULL    |       |

+-------+---------------------------+------+-----+---------+-------+

8 rows in set (0.00 sec)

3.4 修改字段

语法

ALTER TABLE 表名 MODIFY 字段名数据类型[(宽度) 约束条件];

ALTER TABLE 表名 CHANGE 旧字段名新字段名旧数据类型[(宽度) 约束条件];

ALTER TABLE 表名 CHANGE 旧字段名新字段名新数据类型[(宽度) 约束条件];

范例

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(10)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.00 sec)

# 修改job字段的数据类型

mysql> alter table test1 modify job varchar(11);

Query OK, 0 rows affected (0.06 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | varchar(11)           | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.01 sec)

# 修改job字段为hobby字段

mysql> alter table test1 change job hobby varchar(11);

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)                   | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| hobby | varchar(11)           | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.00 sec)

# 修改hobby字段为job字段，且数据类型改为char

mysql> alter table test1 change hobby job char(11);

Query OK, 0 rows affected (0.06 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(11)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.01 sec)

3.5 修改字段排列顺序、在增加的时候指定字段位置

语法

ALTER TABLE 表名 ADD 字段名数据类型 [(宽度) 约束条件] FIRST;

ALTER TABLE 表名 ADD 字段名数据类型 [(宽度) 约束条件] AFTER 字段名;

ALTER TABLE 表名 CHANGE 字段名旧字段名新字段名新数据类型 [(宽度) 约束条件] FIRST;

ALTER TABLE 表名 MODIFY 字段名数据类型 [(宽度) 约束条件] AFTER 字段名;

范例

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(11)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

6 rows in set (0.01 sec)

# 在表的开头添加hobby字段

mysql> alter table test1 add hobby char(10) first;

Query OK, 0 rows affected (0.05 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| hobby | char(10)              | YES  |     | NULL    |       |

| id    | int(11)               | YES  |     | NULL    |       |

| name  | char(10)              | YES  |     | NULL    |       |

| age   | int(11)               | YES  |     | NULL    |       |

| sex   | enum('male','female') | YES  |     | NULL    |       |

| phone | char(11)              | YES  |     | NULL    |       |

| job   | char(11)              | YES  |     | NULL    |       |

+-------+-----------------------+------+-----+---------+-------+

7 rows in set (0.00 sec)

# 在job字段后面添加salary字段

mysql> alter table test1 add salary int after job;

Query OK, 0 rows affected (0.05 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+--------+-----------------------+------+-----+---------+-------+

| Field  | Type                  | Null | Key | Default | Extra |

+--------+-----------------------+------+-----+---------+-------+

| hobby  | char(10)              | YES  |     | NULL    |       |

| id     | int(11)               | YES  |     | NULL    |       |

| name   | char(10)              | YES  |     | NULL    |       |

| age    | int(11)               | YES  |     | NULL    |       |

| sex    | enum('male','female') | YES  |     | NULL    |       |

| phone  | char(11)              | YES  |     | NULL    |       |

| job    | char(11)              | YES  |     | NULL    |       |

| salary | int(11)               | YES  |     | NULL    |       |

+--------+-----------------------+------+-----+---------+-------+

8 rows in set (0.00 sec)

# 修改hobby字段名为aihao

mysql> alter table test1 change hobby aihao char(10) first;

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+--------+-----------------------+------+-----+---------+-------+

| Field  | Type                  | Null | Key | Default | Extra |

+--------+-----------------------+------+-----+---------+-------+

| aihao  | char(10)              | YES  |     | NULL    |       |

| id     | int(11)               | YES  |     | NULL    |       |

| name   | char(10)              | YES  |     | NULL    |       |

| age    | int(11)               | YES  |     | NULL    |       |

| sex    | enum('male','female') | YES  |     | NULL    |       |

| phone  | char(11)              | YES  |     | NULL    |       |

| job    | char(11)              | YES  |     | NULL    |       |

| salary | int(11)               | YES  |     | NULL    |       |

+--------+-----------------------+------+-----+---------+-------+

8 rows in set (0.00 sec)

# 把aihao字段放到salary字段后面

mysql> alter table test1 modify aihao char(10) after salary;

Query OK, 0 rows affected (0.04 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> desc test1;

+--------+-----------------------+------+-----+---------+-------+

| Field  | Type                  | Null | Key | Default | Extra |

+--------+-----------------------+------+-----+---------+-------+

| id     | int(11)               | YES  |     | NULL    |       |

| name   | char(10)              | YES  |     | NULL    |       |

| age    | int(11)               | YES  |     | NULL    |       |

| sex    | enum('male','female') | YES  |     | NULL    |       |

| phone  | char(11)              | YES  |     | NULL    |       |

| job    | char(11)              | YES  |     | NULL    |       |

| salary | int(11)               | YES  |     | NULL    |       |

| aihao  | char(10)              | YES  |     | NULL    |       |

+--------+-----------------------+------+-----+---------+-------+

8 rows in set (0.00 sec)

4.数据操作

创建表

# 创建语句

create table teacher(

id int primary key,

name char(10) not null,

age int,

hire_date datetime,

sex enum('male', 'female') not null default 'male',

phone char(11) unique,

salary float(8, 2),

hobby set('running', 'football', 'basketball'),

comment varchar(255)

);

# 查看表结构

mysql> desc teacher;

+-----------+----------------------------------------+------+-----+---------+-------+

| Field     | Type                                   | Null | Key | Default | Extra |

+-----------+----------------------------------------+------+-----+---------+-------+

| id        | int(11)                                | NO   | PRI | NULL    |       |

| name      | char(10)                               | NO   |     | NULL    |       |

| age       | int(11)                                | YES  |     | NULL    |       |

| hire_date | datetime                               | YES  |     | NULL    |       |

| sex       | enum('male','female')                  | NO   |     | male    |       |

| phone     | char(11)                               | YES  | UNI | NULL    |       |

| salary    | float(8,2)                             | YES  |     | NULL    |       |

| hobby     | set('running','football','basketball') | YES  |     | NULL    |       |

| comment   | varchar(255)                           | YES  |     | NULL    |       |

+-----------+----------------------------------------+------+-----+---------+-------+

9 rows in set (0.00 sec)

4.1 插入数据

语法

插入单行数据，

INSERT INTO 表名 (字段1，字段2，字段3...) value (值1, 值2, 值3);

如果不添加字段名称，插入的数据需要与表里的字段一一对应

INSERT INTO 表名 value (值1, 值2, 值3);

插入多行数据

INSERT INTO 表名 values (值1, 值2, 值3),(值1, 值2, 值3),(值1, 值2, 值3);

范例

#  插入单条数据，注意float类型会进行四舍五入

mysql> insert into teacher (id, name, hobby) value (1, 'zhangsan', 'running');

Query OK, 1 row affected (0.42 sec)

mysql> select * from teacher;

+----+----------+------+-----------+------+-------+--------+---------+---------+

| id | name     | age  | hire_date | sex  | phone | salary | hobby   | comment |

+----+----------+------+-----------+------+-------+--------+---------+---------+

|  1 | zhangsan | NULL | NULL      | male | NULL  |   NULL | running | NULL    |

+----+----------+------+-----------+------+-------+--------+---------+---------+

1 row in set (0.00 sec)

mysql> insert into teacher value (2, 'lisi', 30, '2017-10-20', 'male', '13069948980', 2000, 'basketball', 'haha');

Query OK, 1 row affected (0.15 sec)

mysql> select * from teacher;

+----+----------+------+---------------------+------+-------------+---------+------------+---------+

| id | name     | age  | hire_date           | sex  | phone       | salary  | hobby      | comment |

+----+----------+------+---------------------+------+-------------+---------+------------+---------+

|  1 | zhangsan | NULL | NULL                | male | NULL        |    NULL | running    | NULL    |

|  2 | lisi     |   30 | 2017-10-20 00:00:00 | male | 13069948980 | 2000.00 | basketball | haha    |

+----+----------+------+---------------------+------+-------------+---------+------------+---------+

2 rows in set (0.03 sec)

# 插入多条数据

mysql> insert into teacher values (3, 'wangwu', 28, '2016-11-20', 'male', '1382333333', 20000, 'football', 'wowo'),

    ->  (4, 'xiaoli', 28, '2015-11-20', 'female', '13823333333', 20000, 'football', 'wowo');

Query OK, 2 rows affected (0.40 sec)

Records: 2  Duplicates: 0  Warnings: 0

mysql> select * from teacher;

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

| id | name     | age  | hire_date           | sex    | phone       | salary   | hobby      | comment |

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

|  1 | zhangsan | NULL | NULL                | male   | NULL        |     NULL | running    | NULL    |

|  2 | lisi     |   30 | 2017-10-20 00:00:00 | male   | 13069948980 |  2000.00 | basketball | haha    |

|  3 | wangwu   |   28 | 2016-11-20 00:00:00 | male   | 1382333333  | 20000.00 | football   | wowo    |

|  4 | xiaoli   |   28 | 2015-11-20 00:00:00 | female | 13823333333 | 20000.00 | football   | wowo    |

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

4 rows in set (0.00 sec)

4.2 删除数据

语法

DELETE FROM 表名 WHERE ....;

范例

mysql> select * from teacher;

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

| id | name     | age  | hire_date           | sex    | phone       | salary   | hobby      | comment |

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

|  1 | zhangsan | NULL | NULL                | male   | NULL        |     NULL | running    | NULL    |

|  2 | lisi     |   30 | 2017-10-20 00:00:00 | male   | 13069948980 |  2000.00 | basketball | haha    |

|  3 | wangwu   |   28 | 2016-11-20 00:00:00 | male   | 1382333333  | 20000.00 | football   | wowo    |

|  4 | xiaoli   |   28 | 2015-11-20 00:00:00 | female | 13823333333 | 20000.00 | football   | wowo    |

+----+----------+------+---------------------+--------+-------------+----------+------------+---------+

4 rows in set (0.00 sec)

mysql> delete from teacher where id=1;

Query OK, 1 row affected (0.48 sec)

mysql> select * from teacher;

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

| id | name   | age  | hire_date           | sex    | phone       | salary   | hobby      | comment |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

|  2 | lisi   |   30 | 2017-10-20 00:00:00 | male   | 13069948980 |  2000.00 | basketball | haha    |

|  3 | wangwu |   28 | 2016-11-20 00:00:00 | male   | 1382333333  | 20000.00 | football   | wowo    |

|  4 | xiaoli |   28 | 2015-11-20 00:00:00 | female | 13823333333 | 20000.00 | football   | wowo    |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

3 rows in set (0.00 sec)

4.3 更新数据

语法

UPDATE 表名 SET 字段1=值1, 字段2=值2 WHERE ...;

范例

mysql> select * from teacher;

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

| id | name   | age  | hire_date           | sex    | phone       | salary   | hobby      | comment |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

|  2 | lisi   |   30 | 2017-10-20 00:00:00 | male   | 13069948980 |  2000.00 | basketball | haha    |

|  3 | wangwu |   28 | 2016-11-20 00:00:00 | male   | 1382333333  | 20000.00 | football   | wowo    |

|  4 | xiaoli |   28 | 2015-11-20 00:00:00 | female | 13823333333 | 20000.00 | football   | wowo    |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

3 rows in set (0.00 sec)

mysql> update teacher set age=40 where id=2;

Query OK, 1 row affected (0.46 sec)

Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from teacher;

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

| id | name   | age  | hire_date           | sex    | phone       | salary   | hobby      | comment |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

|  2 | lisi   |   40 | 2017-10-20 00:00:00 | male   | 13069948980 |  2000.00 | basketball | haha    |

|  3 | wangwu |   28 | 2016-11-20 00:00:00 | male   | 1382333333  | 20000.00 | football   | wowo    |

|  4 | xiaoli |   28 | 2015-11-20 00:00:00 | female | 13823333333 | 20000.00 | football   | wowo    |

+----+--------+------+---------------------+--------+-------------+----------+------------+---------+

3 rows in set (0.00 sec)

4.4 查询数据

单表查询

多表查询

03-MySQL表操作的更多相关文章

Python 3 mysql 表操作
Python 3 mysql 表操作表相当于文件,表中的一条记录就相当于文件的一行内容,不同的是,表中的一条记录有对应的标题,称为表的字段 id,name,qq,age称为字段,其余的,一行内容称为 ...
8.3 mysql 表操作
库操作一系统数据库 information_schema: 虚拟库,不占用磁盘空间,存储的是数据库启动后的一些参数,如用户表信息.列信息.权限信息.字符信息等 performance_sch ...
数据库 -- mysql表操作
一,存储引擎介绍存储引擎即表类型,mysql根据不同的表类型会有不同的处理机制详见:https://www.cnblogs.com/peng104/p/9751738.html 二,表介绍表相当 ...
MySQL表操作及数据操作
表操作表相当于一个文件,其形式与现实中的表格相同.表中的每条记录都有相应的字段,字段就类似于表格的表头. 表操作详细: #对表进行操作(文件) #首先要切换到指定库(即文件夹)下:use db1; ...
细说MySQL表操作
目录语法查看表结构查看所有的表删除表查看创建表的语句修改表的字符集和校验规则修改表名在表中添加新字段修改表的字段名修改表中字段的属性删除表中的某个字段设置某个字段为主键把某个 ...
mysql表操作与权限操作
修改表ALTER TABLE 语法: . 修改表名 ALTER TABLE 表名 RENAME 新表名; . 增加字段 ALTER TABLE 表名 ADD 字段名数据类型 [完整性约束条件…], ...
mysql数据库从删库到跑路之mysql表操作
表介绍表相当于文件,表中的一条记录就相当于文件的一行内容,不同的是,表中的一条记录有对应的标题,称为表的字段 id,name,qq,age称为字段,其余的,一行内容称为一条记录内容: 1 创建表 ...
MySQL 表操作（Day40）
阅读目录一.表介绍二.创建表三.查看表四.修改表五.删除表六.操作表中的记录一.表介绍表相当于文件,表中的一条记录就相当于文件的一行内容,不同的是,表中的一条记录有对应的标题,则称为表 ...
Mysql表操作
查看表结构: 可以使用describe或show create table语句查看表的结构: describe表名; Show create table 表名; 修改表名: Alter table 旧 ...
mysql 表操作
创建表简单的方式 CREATE TABLE person ( number INT(11), name VARCHAR(255), birthday DATE ); 或者是 CREATE TABLE ...

随机推荐

【WebGIS系列】Typescript+WebGL+Webpack开发环境搭建
目前Web实现矢量渲染的主流技术包括SVG.VML和WebGL.相对而言,VML是一种较古老的技术,虽然未成为W3C标准,但被早期的IE浏览器(IE9以下)和微软Office广泛使用,目前已经远离了浏 ...
AR增强现实开发介绍（续）
AR增强现实开发介绍(续) ---开发基础篇开发增强现实技术,无论是商业级应用,还是面向幼儿教育的游戏产品,都需要从了解.获取.下载增强现实插件开始.目前全世界使用量最大公认最好的增强现实插件是高通 ...
研究windows下SVN备份及还原恢复方案
windows下SVN备份方案备份策略 svn备份一般采用三种方式: 1)svnadmin dump 2)svnadmin hotcopy 3)svnsync. 注意,svn备份不宜采用普通的 ...
Vmware虚拟机中CentOS7与Docker安装图文教程
1.安装VMware 下载一个软件安装: 2.新建一个虚拟机等待自动安装完成配置系统语言: 配置系统时间: 配置系统键盘: 语言支持: 默认自动使用安装源: 配置软件环境,需要及时添加的软件,这里 ...
.Net Core的Log方式：Serilog+Kibana
前言 Serilog,支持对象,把log数据序列化成Json,好用方便,容易拓展.Github: https://github.com/handsomeyao77/serilog-sinks-elas ...
通过 UI 管理 docker
Docker 正在被用在越来越多的场景中,对于不太习惯命令行工具的朋友来说,docker cli 用起来可能会比较吃力.本文笔者将介绍一个功能强大的 docker web 客户端:portainer( ...
玩转Spring Cloud之配置中心（config server &config client）
本文内容导航: 一.搭建配置服务中心(config server) 1.1.git方式 1.2.svn方式 1.3.本地文件方式 1.4.解决配置中包含中文内容返回乱码问题二.搭建配置消费客户端( ...
Centos7+LVS-DR+keepalived实验（包含sorry-server、日志、及HTTP-GET的健康检测）
目录检索一.简介 1.lvs-dr原理请参考原理篇 2.keepalived原理请参考原理篇 3.基于lvs-dr+keepalived故障切换架构图如下: 二.部署 1.环境 2.准备RS的web ...
Unity MMORPG游戏开发教程（一）——初识Unity
五邑隐侠,本名关健昌,10年游戏生涯,现隐居五邑.本系列文章以C#为介绍语言,基于Unity2017.4.x. 一.环境搭建我使用的是Unity+VSCode,用的是mac系统,windows的自己 ...
SAP 没有激活HUM功能照常可以使用Handling Unit
SAP 没有激活HUM功能照常可以使用Handling Unit 笔者所在的项目上的公司间STO的流程里,发货公司在做PGI之后系统自动触发收货公司的inbound delivery单据,发货公司发出 ...

03-MySQL表操作