数据库学习之将mysql的insert和select操作封装成类

import pymysql

class MyMysql:
    def __init__(self):
        mysql_config = {
                'host':'127.0.0.1',
                'port':3306,
                'user':'root',
                'password':'qwe123',
                'db':'wumou',
                'charset': 'utf8'
                }
        self.conn = pymysql.connect(**mysql_config)
        self.cur = self.conn.cursor()

    def insert(self,tbname,*args):
        '''注意在mysql中，insert语句：insert into tbname values(1,'wuhan',14)
            所以在python操作mysql的insert语句时，要注意将value转换为括号里面放值
            且整个value为字符串类型'''
        args = list(args)
        for i in range(len(args)):
            args[i] = tuple(args[i])
        args = str(args)
        st = args[1:-1]
        sql = f'insert into {tbname} value {st}'
        self.cur.execute(sql)

    def select(self,field,tbname,select_var = 1,**condition):
        '''python操作mysql数据库进行查询操作
            tbname为表名；select_var默认形参为1时是有一个条件查询，为2时是无条件查询,为3是多条件查询
            condition为条件'''
        if select_var == 1:
            for key,value in condition.items():
                condition_new = f"where {key} = '{value}'"
            sql = f'select {field} from {tbname} {condition_new}'
        elif select_var ==2:
            sql = f'select {field} from {tbname}'
        else:
            a = []          #将条件（字典类型）变为列表类型
            for key,value in condition.items():
                a.extend([key,value])

            b = []          #将每个条件中的字段与值用=相连
            for i in range(len(a)):
                if i % 2 == 0:
                    b.append(f"{a[i]} = '{a[i+1]}")
            b = str(b)
                            #切出有用的条件语句
            b = b.replace('", "'," 'and ")
            print('第二次b  ',b)
            sql = f"select {field} from {tbname} where {b[2:-2]}'"

        self.cur.execute(sql)
        for i in self.cur:
            print(i)
            
            #mysql的update和delete方法主要思路如上！！！
    def update(self):
    	pass
    def delete(self):
    pass


    def close(self):
        self.conn.commit()
        self.conn.close()
        self.cur.close()

m = MyMysql()
# m.insert('student',[8,'吴某',2,54,'third'],[9,'中国',3,57,'first'])
m.select('*','student',select_var=3,name = 'zhongguo',age = 18,gradname = 'first')
m.close()

所操作的mysql表示例：

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标签：insert,成类,self,args,tbname,mysql,select
来源： https://blog.csdn.net/qq_44907926/article/details/104541234