基本思路：
①比较库中的表：SHOW TABLES;
②比较表结构：SHOW COLUMNS FROM table;（table置换成具体表名）；
③比较表中数据SELECT * FROM table;
备注：数据量大的时候可以边查询边比较

 # db_connect→由pymysql.connect()构建
    def test_query1(self, db_connect):
        # res→存放结果的字典，也是比较的依据
        res = {}
        # 列信息
        t_col = []
        # 表数据
        t_val = []
        sql = "SHOW tables"
        result = self.sql_query(db_connect, sql)
        res[0] = result
        # 查询列信息
        for i in result:
            sql = f"SHOW COLUMNS FROM {i[0]}"
            col = self.sql_query(db_connect, sql)
            t_col.append(col)
        # 查询表数据
        for j in result:
            sql = f"SELECT * FROM {j[0]};"
            val = self.sql_query(db_connect, sql)
            t_val.append(val)
        res[1] = t_col
        res[2] = t_val
        db_connect.close()
        return res

    def sql_query(self, db_connect, sql):
        # 创建游标
        db_cursor = db_connect.cursor()
        # 执行sql
        db_cursor.execute(sql)
        # 获取查询结果
        result = db_cursor.fetchall()
        # 关闭游标
        db_cursor.close()
        # 提交
        db_connect.commit()
        # 返回查询结果
        return result

    def db_compare(self, db_connect, db_connect1):
        # 比较
        if self.test_query1(db_connect) == self.test_query1(db_connect1):
            print("数据库一致")