本文介绍异步MySQL异步驱动aiomysql的使用
如果没有模块则先使用pip安装模块
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pip3 install asyncio
pip3 install aiomysql
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和同步方式不一样的是使用异步不能直接创建数据库连接conn,需要先创建一个数据库连接池对象__pool通过这个数据库连接池对象来创建数据库连接
数据库配置信息和介绍pymysql同步使用的数据库是一样的
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import asyncio,aiomysql,time
# 数据库配置dict
db_config = {
'host' : 'localhost' ,
'user' : 'www-data' ,
'password' : 'www-data' ,
'db' : 'awesome'
}
# 创建数据库连接池协程函数
async def create_pool( * * kw):
global __pool
__pool = await aiomysql.create_pool(
host = kw.get( 'host' , 'localhost' ),
port = kw.get( 'port' , 3306 ),
user = kw[ 'user' ],
password = kw[ 'password' ],
db = kw[ 'db' ]
)
loop = asyncio.get_event_loop()
loop.run_until_complete(create_pool( * * db_config))
# 在事件循环中运行了协程函数则生成了全局变量__pool是一个连接池对象 <aiomysql.pool.Pool object at 0x00000244AD1724C8>
print (__pool)
# <aiomysql.pool.Pool object at 0x00000244AD1724C8>
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因为是异步模块,只能在事件循环中通过await关键字调用,使用需要创建执行sql语句的协程函数
在协程函数内使用全局上一步创建的连接池对象来创建连接conn和浮标对象cur,通过浮标对象来执行sql语句,执行方法和pymysql模块的执行方法是一样的
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cursor.execute(sql,args)
sql # 需要执行的sql语句例如'select * from table_name'
args # 替换sql语句的格式化字符串,即sql语句可以使用%s代表一个字符串,然后在args中使用对应的变量或参数替换,args为一个list或元组,即是一个有序的序列需要和sql中的%s一一对应
# 例如sql='select * from table_name where id=%s' args=['12345']
# 相当于使用args中的参数替换sql中的%s
# select * from table_name where id='12345'
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下面分别创建两个协程函数select execute一个用来执行搜索操作,一个用来执行insert,update,delete等修改操作
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# 执行select函数
async def select(sql,args,size = None ):
with await __pool as conn:
cur = await conn.cursor(aiomysql.DictCursor)
await cur.execute(sql.replace( '?' , '?s' ),args or ())
if size:
rs = await cur.fetchmany(size)
else :
rs = await cur.fetchall()
await cur.close()
return rs
# 执行insert update delete函数
async def execute(sql,args):
with await __pool as conn:
try :
cur = await conn.cursor()
await cur.execute(sql.replace( '?' , '%s' ),args)
affetced = cur.rowcount
await conn.commit()
await cur.close()
except BaseException as e:
raise
return affetced
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实践执行sql语句前我们首先在本机创建一个数据库和对应的表用于测试
数据库对应的主机,用户名,密码,库名,表名如下
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host: localhost
user: www - data
password: www - data
db:awesome
table_name: users
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创建表名的sql语句如下,需要在数据库中创建好对应的表
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CREATE TABLE `users` (
` id ` varchar( 50 ) NOT NULL,
`email` varchar( 50 ) NOT NULL,
`passwd` varchar( 50 ) NOT NULL,
`admin` tinyint( 1 ) NOT NULL,
`name` varchar( 50 ) NOT NULL,
`image` varchar( 500 ) NOT NULL,
`created_at` double NOT NULL,
PRIMARY KEY (` id `),
UNIQUE KEY `idx_email` (`email`),
KEY `idx_created_at` (`created_at`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8
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创建好的表对应的结构如下
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mysql> desc users;
+ - - - - - - - - - - - - + - - - - - - - - - - - - - - + - - - - - - + - - - - - + - - - - - - - - - + - - - - - - - +
| Field | Type | Null | Key | Default | Extra |
+ - - - - - - - - - - - - + - - - - - - - - - - - - - - + - - - - - - + - - - - - + - - - - - - - - - + - - - - - - - +
| id | varchar( 50 ) | NO | PRI | NULL | |
| email | varchar( 50 ) | NO | UNI | NULL | |
| passwd | varchar( 50 ) | NO | | NULL | |
| admin | tinyint( 1 ) | NO | | NULL | |
| name | varchar( 50 ) | NO | | NULL | |
| image | varchar( 500 ) | NO | | NULL | |
| created_at | double | NO | MUL | NULL | |
+ - - - - - - - - - - - - + - - - - - - - - - - - - - - + - - - - - - + - - - - - + - - - - - - - - - + - - - - - - - +
7 rows in set ( 2.68 sec)
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①执行insert操作
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# insert start
import time
sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
args = [ 'test@qq.com' , 'password' , 1 , 'test' , 'about:blank' ,time.time(), '111111' ]
async def insert():
await execute(sql,args)
loop.run_until_complete(insert())
# insert end
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执行方式和pymysql没有区别,不同的是需要在事件循环中使用关键字await调用
执行完毕在MySQL中查看插入的数据
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mysql> select * from users;
+ - - - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - + - - - - - - - + - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - - - - - - - - - +
| id | email | passwd | admin | name | image | created_at |
+ - - - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - + - - - - - - - + - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - - - - - - - - - +
| 111111 | test@qq.com | password | 1 | test | about:blank | 1637738541.48629 |
+ - - - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - + - - - - - - - + - - - - - - + - - - - - - - - - - - - - + - - - - - - - - - - - - - - - - - - +
1 row in set ( 0.00 sec)
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②执行update操作
直接在loop事件循环中执行execute协程函数也可以
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# update start
import time
sql = 'update `users` set `email`=?, `passwd`=?, `admin`=?, `name`=?, `image`=?, `created_at`=? where `id`=?'
args = [ 'test2@qq.com' , 'password' , 1 , 'test2' , 'about:blank' ,time.time(), '111111' ]
loop.run_until_complete(execute(sql,args))
# update end
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执行以后把email和name都修改了
③执行delete操作
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# delete start
sql = 'delete from `users` where `id`=?'
args = [ '111111' ]
loop.run_until_complete(execute(sql,args))
# delete end
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同样根据关键字id指定的值删除了这条数据
④执行selete操作
在执行select操作前我们保证数据库里面至少有一条数据
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# select start
sql = 'select * from users'
args = []
rs = loop.run_until_complete(select(sql,args))
print (rs)
# select end
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这里直接执行搜索的协程函数select根据函数的定义返回的是所有结果的list,元素是查询结果的字典
输出为
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[{ 'id' : '111111' , 'email' : 'test@qq.com' , 'passwd' : 'password' , 'admin' : 1 , 'name' : 'test' , 'image' : 'about:blank' , 'created_at' : 1637739212.74493 }]
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如果结果有多个则使用list的下标取出
同步模块pymysql和异步模块aiomysql执行速度对比
假如我们需要往数据库插入20000条数据,我们分别使用同步模式和异步模式
首先删除数据库所有测试数据
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delete from users;
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同步的代码
d:/learn-python3/学习脚本/pymysql/use_pymysql.py
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import pymysql
db_config = {
'host' : 'localhost' ,
'user' : 'www-data' ,
'password' : 'www-data' ,
'db' : 'awesome'
}
# 创建连接,相当于把字典内的键值对传递
# 相当于执行pymysql.connect(host='localhost',user='www-data',password='www-data',db='awesome')
conn = pymysql.connect( * * db_config)
# 创建游标
cursor = conn.cursor(pymysql.cursors.DictCursor)
sql = 'select * from users'
args = []
# 执行查询返回结果数量
# 执行查询
rs = cursor.execute(sql,args)
# 获取查询结果
# 获取查询的第一条结果,返回一个dict,dict元素是查询对应的键值对
# 如果查询结果有多条则执行一次,游标移动到下一条数据,在执行一次又返回一条数据
# print(cursor.fetchone())
# print(cursor.fetchone())
# print(cursor.fetchall())
# print(cursor.fetchmany())
# {'id': '111111', 'email': 'test@qq.com', 'passwd': 'password', 'admin': 1, 'name': 'test', 'image': 'about:blank', 'created_at': 1637723578.5734}
# 获取查询的所有结果,返回一个list,list元素是dict,dict元素是查询对应的键值对
# print(cursor.fetchall())
# [{'id': '111111', 'email': 'test@qq.com', 'passwd': 'password', 'admin': 1, 'name': 'test', 'image': 'about:blank', 'created_at': 1637723578.5734}]
# 获取查询的前几条结果,返回一个dict,dict元素是查询对应的键值对
# print(cursor.fetchmany(1))
# [{'id': '111111', 'email': 'test@qq.com', 'passwd': 'password', 'admin': 1, 'name': 'test', 'image': 'about:blank', 'created_at': 1637723578.5734}]
# 执行修改操作
import time
# # insert start
sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
args = [ 'test1@qq.com' , 'password' , 1 , 'test' , 'about:blank' ,time.time(), '1111121' ]
# 使用replace 把'?'替换成'%s'
# rs = cursor.execute(sql.replace('?','%s'),args)
# print(cursor.rowcount)
# conn.commit()
# print(rs)
# insert end
# update start
# sql = 'update `users` set `email`=?, `passwd`=?, `admin`=?, `name`=?, `image`=?, `created_at`=? where `id`=?'
# args = ['test2@qq.com','password',1,'test2','about:blank',time.time(),'111111']
# print(cursor.execute(sql.replace('?','%s'),args))
# conn.commit()
# update end
# delete start
# sql = 'delete from `users` where `id`=?'
# args = ['111111']
# print(cursor.execute(sql.replace('?','%s'),args))
# conn.commit()
# delete end
# 写成函数调用,函数内部使用了数据库连接对象conn
# 可以先定义成全局变量global
def select(sql,args,size = None ):
cursor = conn.cursor(pymysql.cursors.DictCursor)
cursor.execute(sql.replace( '?' , '%s' ),args or ())
if size:
rs = cursor.fetchmany(size)
else :
rs = cursor.fetchall()
cursor.close
# logging.info('rows returned: %s' % len(rs))
return rs
def execute(sql,args):
cursor = conn.cursor(pymysql.cursors.DictCursor)
try :
cursor.execute(sql.replace( '?' , '%s' ),args)
# rowcount方法把影响函数返回
rs = cursor.rowcount
cursor.close()
conn.commit()
except :
raise
return rs
start_time = time.time()
for n in range ( 20000 ):
sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
email = 'test%s@qq.com' % n
args = [email, 'password' , 1 , 'test' , 'about:blank' ,time.time(),n]
execute(sql,args)
end_time = time.time()
# 打印开始和结束时间的差
print (end_time - start_time)
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我们使用一个循环20000次往数据库插入数据
执行,插入数据比较多需要等待一段时间输出
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D:\learn - python3\函数式编程>C: / Python37 / python.exe d: / learn - python3 / 学习脚本 / pymysql / use_pymysql.py
77.46903562545776
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可以在数据库查询到这20000条数据,而且这个表的字段created_at存储了创建这条数据的时间戳,我们可以看到,id越往后的时间戳越往后,说明数据是同步按顺序一一插入的
我们按照字段created_at排序查询
下面我们删除所有数据使用异步方式插入
异步的代码如下
d:/learn-python3/学习脚本/aiomysql/use_aiomysql.py
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import asyncio,aiomysql,time
# 数据库配置dict
db_config = {
'host' : 'localhost' ,
'user' : 'www-data' ,
'password' : 'www-data' ,
'db' : 'awesome'
}
# 创建数据库连接池协程函数
async def create_pool( * * kw):
global __pool
__pool = await aiomysql.create_pool(
host = kw.get( 'host' , 'localhost' ),
port = kw.get( 'port' , 3306 ),
user = kw[ 'user' ],
password = kw[ 'password' ],
db = kw[ 'db' ]
)
loop = asyncio.get_event_loop()
loop.run_until_complete(create_pool( * * db_config))
# 在事件循环中运行了协程函数则生成了全局变量__pool是一个连接池对象 <aiomysql.pool.Pool object at 0x00000244AD1724C8>
print (__pool)
# <aiomysql.pool.Pool object at 0x00000244AD1724C8>
# 执行select函数
async def select(sql,args,size = None ):
with await __pool as conn:
cur = await conn.cursor(aiomysql.DictCursor)
await cur.execute(sql.replace( '?' , '?s' ),args or ())
if size:
rs = await cur.fetchmany(size)
else :
rs = await cur.fetchall()
await cur.close()
return rs
# 执行insert update delete函数
async def execute(sql,args):
with await __pool as conn:
try :
cur = await conn.cursor()
await cur.execute(sql.replace( '?' , '%s' ),args)
affetced = cur.rowcount
await conn.commit()
await cur.close()
except BaseException as e:
raise
return affetced
# insert start
# import time
# sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
# args = ['test@qq.com','password',1,'test','about:blank',time.time(),'111111']
# async def insert():
# await execute(sql,args)
# loop.run_until_complete(insert())
# insert end
# update start
# import time
# sql = 'update `users` set `email`=?, `passwd`=?, `admin`=?, `name`=?, `image`=?, `created_at`=? where `id`=?'
# args = ['test2@qq.com','password',1,'test2','about:blank',time.time(),'111111']
# loop.run_until_complete(execute(sql,args))
# update end
# delete start
# sql = 'delete from `users` where `id`=?'
# args = ['111111']
# loop.run_until_complete(execute(sql,args))
# delete end
# select start
# sql = 'select * from users'
# args = []
# rs = loop.run_until_complete(select(sql,args))
# print(rs)
# select end
async def insert1():
for n in range ( 10000 ):
sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
email = 'test%s@qq.com' % n
args = [email, 'password' , 1 , 'test' , 'about:blank' ,time.time(),n]
await execute(sql,args)
async def insert2():
for n in range ( 10001 , 20001 ):
sql = 'insert into `users` (`email`, `passwd`, `admin`, `name`, `image`, `created_at`, `id`) values (?, ?, ?, ?, ?, ?, ?)'
email = 'test%s@qq.com' % n
args = [email, 'password' , 1 , 'test' , 'about:blank' ,time.time(),n]
await execute(sql,args)
async def main():
# 需要组合成一个事件才会异步执行即在执行insert1的时候同步执行insert2
await asyncio.gather(insert1(),insert2())
start_time = time.time()
loop.run_until_complete(main())
end_time = time.time()
print (end_time - start_time)
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这里我们定义了两个协程函数,分别用来执行前10000个数据和后10000个数据的插入,在main()把这两个协程函数组合成一个事件循环
等待一段时间后执行输出如下,忽略这个warning,可以看到执行时间明显比同步时间短
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d: / learn - python3 / 学习脚本 / aiomysql / use_aiomysql.py: 42 : DeprecationWarning: with await pool as conn deprecated, useasync with pool.acquire() as conn instead
with await __pool as conn:
39.794615507125854
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我们去数据库查询一下数据也可以看到id从0开始和id从10001开始几乎是同时插入的