Python 2 和 Python 3 操作 MySQL 数据库实现创建表删除表增删改查操作
Posted 魏晓蕾
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1、mysql数据库和表的编码格式
（1）创建数据库并指定字符集
mysql> create database testpythondb character set utf8;
Query OK, 1 row affected, 1 warning (0.60 sec)
（2）查看数据库的编码格式
mysql> show variables like 'character_set_database';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| character_set_database | utf8 |
+------------------------+-------+
1 row in set (0.10 sec)
（3）创建表并指定字符集
mysql> create table tb_books (
-> id varchar(10) not null,
-> name varchar(20) not null,
-> author varchar(20) not null,
-> price double not null) default charset = utf8;
Query OK, 0 rows affected, 1 warning (2.16 sec)
mysql> show tables;
+------------------------+
| Tables_in_testpythondb |
+------------------------+
| tb_books |
+------------------------+
1 row in set (0.17 sec)
mysql> desc tb_books;
+--------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| name | varchar(20) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
+--------+-------------+------+-----+---------+-------+
4 rows in set (0.10 sec)
（4）查看数据表的编码格式
mysql> show create table tb_books;
+----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) NOT NULL,
`name` varchar(20) NOT NULL,
`author` varchar(20) NOT NULL,
`price` double NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.10 sec)
（5）修改数据库的编码格式
mysql> alter database testpythondb character set gbk;
Query OK, 1 row affected (0.17 sec)
mysql> show variables like 'character_set_database';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| character_set_database | gbk |
+------------------------+-------+
1 row in set (0.06 sec)
（6）修改数据表的编码格式
mysql> alter table tb_books character set gbk;
Query OK, 0 rows affected (0.31 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table tb_books;
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) CHARACTER SET utf8 NOT NULL,
`name` varchar(20) CHARACTER SET utf8 NOT NULL,
`author` varchar(20) CHARACTER SET utf8 NOT NULL,
`price` double NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
（7）修改字段的编码格式
mysql> alter table tb_books change name bookname varchar(25) character set gbk not null;
Query OK, 0 rows affected, 1 warning (0.18 sec)
Records: 0 Duplicates: 0 Warnings: 1
mysql> desc tb_books;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| bookname | varchar(25) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
+----------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> show create table tb_books;
+----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) CHARACTER SET utf8 NOT NULL,
`bookname` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NOT NULL,
`author` varchar(20) CHARACTER SET utf8 NOT NULL,
`price` double NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
（8）添加表外键
mysql> create table tb_bookstore (
-> storeid varchar(10) not null,
-> storename varchar(20) not null,
-> address varchar(50) not null);
Query OK, 0 rows affected (1.02 sec)
mysql> show tables;
+------------------------+
| Tables_in_testpythondb |
+------------------------+
| tb_books |
| tb_bookstore |
+------------------------+
2 rows in set (0.00 sec)
mysql> show create table tb_bookstore;
+--------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+--------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_bookstore | CREATE TABLE `tb_bookstore` (
`storeid` varchar(10) NOT NULL,
`storename` varchar(20) NOT NULL,
`address` varchar(50) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+--------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> alter table tb_bookstore add constraint idx_id primary key (storeid);
Query OK, 0 rows affected (1.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc tb_bookstore;
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| storeid | varchar(10) | NO | PRI | NULL | |
| storename | varchar(20) | NO | | NULL | |
| address | varchar(50) | NO | | NULL | |
+-----------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
mysql> alter table tb_books add storeid varchar(10) not null;
Query OK, 0 rows affected (0.46 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc tb_books;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| bookname | varchar(25) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
| storeid | varchar(10) | NO | | NULL | |
+----------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
mysql> alter table tb_books add constraint fk_book_store foreign key(storeid) references tb_bookstore(storeid);
Query OK, 0 rows affected (1.89 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc tb_books;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| bookname | varchar(25) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
| storeid | varchar(10) | NO | MUL | NULL | |
+----------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
mysql> show create table tb_books;
+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) CHARACTER SET utf8 NOT NULL,
`bookname` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NOT NULL,
`author` varchar(20) CHARACTER SET utf8 NOT NULL,
`price` double NOT NULL,
`storeid` varchar(10) NOT NULL,
KEY `fk_book_store` (`storeid`),
CONSTRAINT `fk_book_store` FOREIGN KEY (`storeid`) REFERENCES `tb_bookstore` (`storeid`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
（9）删除表外键
mysql> alter table tb_books drop foreign key fk_book_store;
Query OK, 0 rows affected (0.17 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table tb_books;
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) CHARACTER SET utf8 NOT NULL,
`bookname` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NOT NULL,
`author` varchar(20) CHARACTER SET utf8 NOT NULL,
`price` double NOT NULL,
`storeid` varchar(10) NOT NULL,
KEY `fk_book_store` (`storeid`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> desc tb_books;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| bookname | varchar(25) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
| storeid | varchar(10) | NO | MUL | NULL | |
+----------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
mysql> alter table tb_books drop key fk_book_store;
Query OK, 0 rows affected (0.24 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc tb_books;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id | varchar(10) | NO | | NULL | |
| bookname | varchar(25) | NO | | NULL | |
| author | varchar(20) | NO | | NULL | |
| price | double | NO | | NULL | |
| storeid | varchar(10) | NO | | NULL | |
+----------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
mysql> show create table tb_books;
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tb_books | CREATE TABLE `tb_books` (
`id` varchar(10) CHARACTER SET utf8 NOT NULL,
`bookname` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NOT NULL,
`author` varchar(20) CHARACTER SET utf8 NOT NULL,
`price` double NOT NULL,
`storeid` varchar(10) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
（10）删除数据库
mysql> drop database testpythondb;
Query OK, 2 rows affected (0.62 sec)
2、PyCharm默认编码格式设置
3、Python 2 操作 MySQL 数据库
- 安装MySQL-python-1.2.5.win32-py2.7.exe，下载地址：https://pypi.org/project/MySQL-python/#files
在 Python 2.7 环境下，pip install mysql报错，故只能安装MySQL-python程序。 - 连接数据库
# coding=utf-8
import MySQLdb
connection = MySQLdb.connect(user='root', passwd='123456', db='testpythondb')
cursor = connection.cursor()
cursor.execute("SELECT VERSION()")
result = cursor.fetchone()
print "数据库版本：{}".format(result)
connection.close()
输出：
数据库版本：('5.7.35',)
Python 2.7 只能连接 MySQL 5.x 版本。
本机 MySQL 5.7.35 和 MySQL 8.0.21 版本切换方式：
修改注册表：Computer\\HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\MySQL\\ImagePath，编辑该文件，“G:\\Program Files\\mysql-5.7.35-win32\\bin\\mysqld” MySQL为MySQL 5.7.35版本，“E:\\Program Files\\mysql-8.0.21-winx64\\bin\\mysqld” MySQL为MySQL 8.0.21 版本。
- 删除表、创建表
# coding=utf-8
import MySQLdb
connection = MySQLdb.connect(user='root', passwd='123456', db='testpythondb')
cursor = connection.cursor()
cursor.execute("DROP TABLE IF EXISTS tb_books")
sql = "create table tb_books ( \\
id varchar(10) not null, \\
name varchar(20) not null, \\
author varchar(20) not null, \\
price double not null) default charset = utf8"
cursor.execute(sql)
connection.close()
mysql> show tables;
+------------------------+
| Tables_in_testpythondb |
+------------------------+
| tb_books |
+------------------------+
1 row in set (0.00 sec)
- INSERT操作
# coding=utf-8
# import sys
import MySQLdb
# reload(sys)
# sys.setdefaultencoding("utf-8")
connection = MySQLdb.connect(user='root', passwd='123456', db='testpythondb', charset='utf8')
cursor = connection.cursor()
sql1 = "insert into tb_books (id, name, author, price) values ('1', '呼啸山庄', '艾米莉·勃朗特', 80.5)"
sql2 = "insert into tb_books (id, name, author, price) values('%s', '%s', '%s', '%g')" % ("2", "老人与海", "欧内斯特·米勒尔·海明威", 88.2)
try:
cursor.execute(sql1)
cursor.execute(sql2)
connection.commit()
except:
connection.rollback()
connection.close()
mysql> select * from tb_books;
+----+--------------+------------------------------------+-------+
| id | name | author | price |
+----+--------------+------------------------------------+-------+
| 1 | 呼啸山庄 | 艾米以上是关于Python 2 和 Python 3 操作 MySQL 数据库实现创建表删除表增删改查操作的主要内容，如果未能解决你的问题，请参考以下文章