import pymysql

class MySQLDB():
    def __init__(self,*args,
                 host='localhost',
                 user='root',
                 password=None,
                 port=3306,
                 db='mysql',
                 charset='utf8',
                 ):
        self.conn = pymysql.connect(user=user,host=host,port=port,password=password,db=db,charset=charset,cursorclass=pymysql.cursors.DictCursor)
        self.cursor = self.conn.cursor()
    def DML(self,sql,condition,mode):
        try:
            if mode == 'insert':
                if len(condition) > 1:
                    result = self.cursor.executemany(sql,condition)
                else:
                    result = self.cursor.execute(sql, condition)
                print(f'插入完成，受影响{result}行')
            if mode == 'update':
                result = self.cursor.execute(sql)
                print(f'更新完成，受影响{result}行')
            if mode == 'delete':
                result = self.cursor.execute(sql)
                print(f'删除完成，受影响{result}行')
            self.conn.commit()
        except pymysql.MySQLError as e:
            self.conn.rollback()
            print(e)
        finally:
            self.conn.close()
    def DQL(self,sql,size=None):
        try:
            result = self.cursor.execute(sql)
            if size:
                result2 = self.cursor.fetchmany(size)
            else:
                result2 = self.cursor.fetchall()
            for i in result2:
                for v in i.values():
                    print(v,end='\t')
                print()
            print(f'共查找{result}条记录')
        except pymysql.MySQLError as e:
            print(e)
        finally:
            self.conn.close()
    def __str__(self):
        return '详细操作手册查看 https://www.baidu.com'
a = MySQLDB(host='39.103.141.138',user='eval',password='123456',db='db1')
a.DQL('select id,name from user')