Python 操作 MySQL | 易学教程

开发环境与配置

win_x64
Ubuntu14.04
Python3.x

直接使用pip安装 pip install pymysql
win64上直接在cmd中执行

使用模块pymysql连接数据库
本地数据库相关配置请参阅： http://rustfisher.github.io/2017/02/25/backend/MySQL_install/

#!/usr/bin/python # coding=utf-8 import pymysql  # 连接本地数据库 conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='yourpwd', db='samp_db1', charset='utf8') cursor = conn.cursor() cursor.execute('select * from bigstu') for row in cursor.fetchall():     print(row)  # 查 cursor.execute('select id, name from bigstu where age > 22') for res in cursor.fetchall():     print(str(res[0]) + ", " + res[1])  cursor.close() print('-- end --')

输出：

(1, '张三', '男', 24, datetime.date(2017, 3, 29), '13666665555') (6, '小刚', '男', 23, datetime.date(2017, 3, 11), '778899888') (8, '小霞', '女', 20, datetime.date(2017, 3, 13), '13712345678') (12, '小智', '男', 21, datetime.date(2017, 3, 7), '13787654321') 1, 张三 6, 小刚 -- end --

可以直接执行sql语句。获得的结果是元组。

sql相似条件查询

SELECT * FROM anindex.subject_basic_table where season_id having '2018';

插入一条数据，接上面的代码

insertSql = "insert into bigstu (name, sex, age,  mobile) values ('%s','%s',%d,'%s') " xiuji = ('秀吉', '男', 15, '13400001111') cursor.execute(insertSql % xiuji) conn.commit() # 别忘了提交

在mobile后面添加一列cash

addCo = "alter table bigstu add cash int after mobile" cursor.execute(addCo)

如果要设置默认值

addCo = "alter table bigstu add cash int default 0 after mobile" cursor.execute(addCo)

删除 name=秀吉的数据

deleteSql = "delete from bigstu where name = '%s'" cursor.execute(deleteSql % '秀吉')

删除cash列

dropCo = "alter table bigstu drop cash" cursor.execute(dropCo)

更新符合条件的数据

updateSql = "update bigstu set sex = '%s' where name = '%s'" updateXiuji = ('秀吉', '秀吉') # 秀吉的性别是秀吉 cursor.execute(updateSql % updateXiuji) conn.commit()

给某个记录的cash增加

table = "bigstu" addCash = "update " + table + " set cash = cash + '%d' where name = '%s'" lucky = (1000, "秀吉")  try:     cursor.execute(addCash % lucky) except Exception as e:     conn.rollback()     print("加钱失败了") else:     conn.commit()

直接执行SQL语句，十分方便

从json中读取需要添加的列名，获取当前2个表中所有的列名
整理得出需要插入的列名，然后将列插入到相应的表中

import pymysql import json import os import secureUtils  mapping_keys = json.load(open("key_mapping_db.json", "r")) db_keys = []  # json中所有的key  for k in mapping_keys.values():     db_keys.append(k)  conn = pymysql.connect(host='localhost', port=3306, user='root',                        passwd='*****', db='db_name', charset='utf8')  cursor = conn.cursor() table_main = "table_main" main_table_keys = []  # 主表的列名 cursor.execute("show columns from " + table_main) for row in cursor.fetchall():     main_table_keys.append(row[0])  staff_table_keys = [] cursor.execute("show columns from table_second") for row in cursor.fetchall():     staff_table_keys.append(row[0])  need_to_insert_keys = [] for k in db_keys:     if k not in staff_table_keys and k not in main_table_keys and k not in need_to_insert_keys:         need_to_insert_keys.append(k)  print("need to insert " + str(len(need_to_insert_keys))) print(need_to_insert_keys) for kn in need_to_insert_keys:     print("add key to db " + kn)     cursor.execute("alter table staff_table add " + kn +" text")  conn.close()

这里将main_table_keys中的所有字段改为utf8

# change column character set to utf8 for co in main_table_keys:     change_sql = "alter table " + table_main + " modify " + co + " text character set utf8"     print(change_sql)     cursor.execute(change_sql)

来源：博客园

作者：RustFisher

链接：https://www.cnblogs.com/rustfisher/p/11750394.html

标签

mysql update语句

pymysql

python

table

keys

mysql数据库