版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/myt2000/article/details/79664959
pymysql的连接
连接数据库
import pymysql
settings = {
'host':'192.168.137.108',
'port':3306,
'user':'tornado',
'password':'tornado',
'db':'tornado',
'charset':'utf8'
}
conn = pymysql.connect(**settings)
print(conn)
#<pymysql.connections.Connection object at 0x000001D3141E5C88>
cursor = conn.cursor()
cursor.execute('show databases')
# one = cursor.fetchone() #取出一条数据
all = cursor.fetchall() #取出所有数据
# print(one)
print(all)
table = '''
create table user(
id int PRIMARY KEY auto_increment,
username VARCHAR(20) not null,
password VARCHAR(20) not null
)
'''
'''
显示sql语句的方法一
mysql> show create table user;
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| user | CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(20) NOT NULL,
`password` varchar(20) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
显示sql语句方法二
mysql> desc user;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| username | varchar(20) | NO | | NULL | |
| password | varchar(20) | NO | | NULL | |
+----------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
'''
# cursor.execute(table) #创建完成后注释掉，否则报错表存在插入值
### 插入值
sql = 'insert into user(username,password) values (%s,%s)'
# cursor.execute(sql,('李四','qwe123'))
# cursor.executemany(sql,[('王五','abc123'),('赵六','333444')])
# conn.commit()
'''
+----+----------+----------+
| id | username | password |
+----+----------+----------+
| 2 | zhangsan | qwe123 |
| 3 | zhangsan | qwe123 |
| 4 | 李四 | qwe123 |
| 5 | 王五 | abc123 |
| 6 | 赵六 | 333444 |
+----+----------+----------+
'''修改值
sql2 = 'update user SET username=%s where id=%s'
# cursor.execute(sql2,('张三',2))
# conn.commit()
'''
+----+----------+----------+
| id | username | password |
+----+----------+----------+
| 2 | 张三 | qwe123 |
| 3 | zhangsan | qwe123 |
| 4 | 李四 | qwe123 |
| 5 | 王五 | abc123 |
| 6 | 赵六 | 333444 |
+----+----------+----------+
'''删除值
sql3 = 'delete from user WHERE id=%s'
cursor.executemany(sql3,[(3,),(6,)])
conn.commit()
'''
+----+----------+----------+
| id | username | password |
+----+----------+----------+
| 2 | 张三 | qwe123 |
| 4 | 李四 | qwe123 |
| 5 | 王五 | abc123 |
+----+----------+----------+
'''