python对mysql进行简单操作

python 连接MySQL数据库，进行简单操作

一、连接MySQL数据库，关闭连接

import pymysql
   
db = pymysql.connect(host="xxx.xxx.x.x",    # 数据库ip地址
                     port=1233,    # 端口号
                     user="root",    # 用户名
                     passwd="*****",    # 密码
                     db="数据库名称",    # 数据库名称
                     charset="utf-8")    # 编码

db.close()    # 关闭MySQL连接

二、进行查询操作

import pymysql

db = pymysql.connect(host="xxx.xxx.x.x",    # 数据库ip地址
                     port=1233,    # 端口号
                     user="root",    # 用户名
                     passwd="*****",    # 密码
                     db="数据库名称",    # 数据库名称
                     charset="utf-8")    # 编码

cur = db.cursor()    # 创建一个游标对象
cur.execute("sql查询语句")    # 执行MySQL语句
data = cur.fetchall()    # 获取查询结果
print(data)
cur.close()    # 关闭游标

三、进行修改操作

import pymysql

db = pymysql.connect(host="xxx.xxx.x.x",    # 数据库ip地址
                     port=1233,    # 端口号
                     user="root",    # 用户名
                     passwd="*****",    # 密码
                     db="数据库名称",    # 数据库名称
                     charset="utf-8")    # 编码

cur = db.cursor()    # 创建一个游标对象
cur.execute("sql修改语句")    # 执行MySQL修改语句
db.commit()    # 一定要提交，不然数据库不会修改成功
cur.close()    # 关闭游标

对MySQL进行查询、修改、将对应的值提取出来

 # coding:utf-8
 import pymysql

 mysql_info = {"host": "xx.xxx.xxx.x",
               "port": 1234,
               "user": "root",
               "passwd": "root",
               "db": "xxxx",
               "charset": "utf8"}

 class TestMySQL(object):
     """连接MySQL，对MySQL进行增删改查操作"""
     def __init__(self):
         """连接池方式"""
         db_info = mysql_info
         self.db = TestMySQL.__get_concent(db_info)

     def __get_concent(db_info):
         """从连接池中取出连接"""
         try:
             # 打开数据库链接
             db = pymysql.connect(host=mysql_info["host"],
                                  port=mysql_info["port"],
                                  user=mysql_info["user"],
                                  passwd=mysql_info["passwd"],
                                  db=mysql_info["db"],
                                  charset=mysql_info["charset"])
             return db
         except Exception as a:
             print("链接数据库异常：%s" % a)

     def select_mysql(self, sql):
         """查询MySQL数据"""
         # 使用 cursor() 方法创建一个游标对象 cur
         cur = self.db.cursor()
         try:
             # 使用 execute() 方法执行 SQL 查询
             cur.execute(sql)
         except Exception as a:
             print("执行MySQL语句出现异常：%s" % a)
         else:
             # 使用 fetchall() 方法获取查询结果
             data = cur.fetchall()
             cur.close()  # 关闭游标
             return data

     def modify_mysql(self, sql):
         """修改MySQL数据，可以进行插入、更新、删除操作"""
         # 使用 cursor() 方法创建一个游标对象 cur
         cur = self.db.cursor()
         try:
             cur.execute(sql)
         except Exception as a:
             print("执行MySQL语句出现异常：%s" % a)
         else:
             # 一定要提交，否则不生效
             self.db.commit()
             cur.close()

     def getstring_mysql(self, sql):
         """从查询结果取出某个对应字段的值"""
         data = self.select_mysql(sql)
         if data is not None:
             for i in data:
                 for j in i:
                     return j

     def close_mysql(self):
         """断开MySQL连接"""
         try:
             self.db.close()
         except Exception as a:
             print("关闭数据库异常：%s" % a)

 if __name__ == '__main__':
     insert_sql = "insert student (id, name, age, sex) VALUES (7, '珠儿a', 20, 1)"
     update_sql = "update student set name='王语嫣', sex=1 where id = 7"
     delete_sql = "delete from student where id = 7"
     select_sql = "select * from student"
     getdata_sql = "select name from student where id=1"

     test_mysql = TestMySQL()
     test_mysql.modify_mysql(insert_sql)
     insert = test_mysql.select_mysql(select_sql)
     print(insert)

     test_mysql.modify_mysql(update_sql)
     update = test_mysql.select_mysql(select_sql)
     print(update)

     test_mysql.modify_mysql(delete_sql)
     delete = test_mysql.select_mysql(select_sql)
     print(delete)

     getdata = test_mysql.getstring_mysql(getdata_sql)
     print(getdata)