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)