转载 Python 操作 MySQL 的正确姿势 - 琉璃块
Python 操作 MySQL 的正确姿势
收录待用，修改转载已取得腾讯云授权
作者 |邵建永
编辑 | 顾乡
使用Python进行MySQL的库主要有三个，Python-MySQL（更熟悉的名字可能是MySQLdb），PyMySQL和SQLAlchemy。
Python-MySQL资格最老，核心由C语言打造，接口精炼，性能最棒，缺点是环境依赖较多，安装复杂，近两年已停止更新，只支持Python2，不支持Python3。
PyMySQL为替代Python-MySQL而生，纯python打造，接口与Python-MySQL兼容，安装方便，支持Python3。
SQLAlchemy是一个ORM框架，它并不提供底层的数据库操作，而是要借助于MySQLdb、PyMySQL等第三方库来完成，目前SQLAlchemy在Web编程领域应用广泛。
本文主要介绍PyMySQL的正确使用方法，示例代码都是选自实战项目。
安装
简单的方式：
pip install pymysql
如果无法联网，需要进行离线安装，例如：
pip install pymysql-x.x.x.tar.gz
导入
import pymysql
连接
def connect_wxremit_db():
return pymysql.connect(host='10.123.5.28',
port=3306,
user='root',
password='root1234',
database='db_name',
charset='latin1')
查询
def query_country_name(cc2):
sql_str = ("SELECT Fcountry_name_zh"
+ " FROM t_country_code"
+ " WHERE Fcountry_2code='%s'" % (cc2))
logging.info(sql_str)
con = mysql_api.connect_wxremit_db()
cur = con.cursor()
cur.<span class="hljs-built_in">execute</span>(sql_str)
rows = cur.fetchall()
cur.<span class="hljs-built_in">close</span>()
con.<span class="hljs-built_in">close</span>()
<span class="hljs-built_in">assert</span> <span class="hljs-built_in">len</span>(rows) == <span class="hljs-number">1</span>, <span class="hljs-string">'Fatal error: country_code does not exists!'</span>
<span class="hljs-keyword">return</span> rows[<span class="hljs-number">0</span>][<span class="hljs-number">0</span>]
简单插入
def insert_file_rec(self, file_name, file_md5):
con = mysql_api.connect_wxremit_db()
cur = con.cursor()
try:
sql_str = ("INSERT INTO t_forward_file (Ffile_name, Ffile_md5)",
+ " VALUES ('%s', '%s')" % (file_name, file_md5))
cur.execute(sql_str)
con.commit()
except:
con.rollback()
logging.exception('Insert operation error')
raise
finally:
cur.close()
con.close()
批量插入
remit_ids = [('1234', 'CAD'), ('5678', 'HKD')]
con = mysql_api.connect_wxremit_db()
cur = con.cursor()
try:
cur.executemany("INSERT INTO t_order (Fremit_id, Fcur_type, Fcreate_time"
+ " VALUES (%s, %s, now())", new_items)
assert cur.rowcount == len(remit_ids), 'my error message'
con.commit()
except Exception as e:
con.rollback()
logging.exception('Insert operation error')
finally:
cur.close()
con.close()
更新
def update_refund_trans(self, remit_id):
con = mysql_api.connect_wxremit_db()
cur = con.cursor()
try:
sql_str = ("SELECT Fremit_id"
+ " FROM t_wxrefund_trans"
+ " WHERE Fremit_id='%s'" % remit_id
+ " FOR UPDATE")
logging.info(sql_str)
cur.execute(sql_str)
<span class="hljs-keyword">assert</span> cur.rowcount == <span class="hljs-number">1</span>, <span class="hljs-string">'Fatal error: The wx-refund record be deleted!'</span>
sql_str = (<span class="hljs-string">"UPDATE t_wxrefund_trans"</span>
+ <span class="hljs-string">" SET Fcheck_amount_flag=1"</span>
+ <span class="hljs-string">", Fmodify_time=now()"</span>
+ <span class="hljs-string">" WHERE Fremit_id='%s'"</span> % remit_id
logging.info(sql_str)
cur.execute(sql_str)
<span class="hljs-keyword">assert</span> cur.rowcount == <span class="hljs-number">1</span>, <span class="hljs-string">'The number of affected rows not equal to 1'</span>
con.commit()
<span class="hljs-keyword">except</span>:
con.rollback()
logging.exception(<span class="hljs-string">'Update operation error'</span>)
<span class="hljs-keyword">raise</span>
<span class="hljs-keyword">finally</span>:
cur.close()
con.close()
PyMySQL已经相当成熟，和Python-MySQL一样，它在很多Linux发行版本中都是可选的安装组件。
</div>
<div class="postDesc">posted @ <span id="post-date">2017-04-25 21:26</span> <a href="https://www.cnblogs.com/liuliliuli2017/">琉璃块</a> 阅读(<span id="post_view_count">12782</span>) 评论(<span id="post_comment_count">0</span>) <a href="https://i.cnblogs.com/EditPosts.aspx?postid=6763988" rel="nofollow">编辑</a> <a href="#" onclick="AddToWz(6763988);return false;">收藏</a></div>
</div>
