用Python编写的CRUD。。。索引器错误：元组索引超出范围

我必须使用Python进行一些选择和更新。这是一门全新的语言，在执行以下（简单）查询时，我在语法方面遇到了一些问题：

以下是我的方法

    def retrieve(self, key):
        cursor = self._db.execute('select  from {}'.format(self._table))
        return dict(cursor.fetchone())

    def update(self, row):
        self._db.execute(
            'update {} set BASE_PRICE = ? where {}'.format(self._table), 
            (row['BASE_PRICE'], row['where']))
        self._db.commit()

    def disp_rows(self):
        cursor = self._db.execute('select IDENT, CONTRACT_CLASS, BASE_PRICE from {} order 
        by BASE_PRICE'.format(self._table))
        for row in cursor:
            print('  {}: {}: {}'.format(row['IDENT'], row['CONTRACT_CLASS'], 
            row['BASE_PRICE']))

    def __iter__(self):
        cursor = self._db.execute('select * from {} order by  
        BASE_PRICE'.format(self._table))
        for row in cursor:
            yield dict(row)


    def main():
    db_cities = database(filename = 'insurance.sqlite', table = 'CITIES')
    db= database(filename = 'insurance.sqlite', table = 'CONTRACTS')
    db_cars = database(filename = 'insurance.sqlite', table = 'CARS')

    print('Retrieve rows')
    for row in db: print(row)

    print('Update rows')
    db.update({'where': 'CONTRACT_CLASS' >= 10', 'BASE_PRICE'= 1000})
    for row in db: print(row)

    print('Retrieve rows after update')
    for row in db: print(row)

Thanks in advance for your help!

---

您在

self.\u表

后面放错了括号

'UPDATE{table\u name}SET BASE\u PRICE={BASE\u PRICE}其中{condition}'。格式(
表\u name=self.\u表，
基准价格=行[“基准价格”]，
条件=行['where']
)

我还做了一些代码清理

---

另一个问题：为什么不使用ORM？

您现在了解了

format（）

的用法了吗？事实上，我在大括号中使用名称的方式更加灵活，没有大括号也可以工作，但可读性不是很好。当我必须进行SQL联接时，如何在db.execute中引用多个表？def retrieve（self，key）：cursor=self.\u db.execute（'select*from{}.format（self.\u table））返回dict（cursor.fetchone（））'def retrieveSmCityCust（self，key）：cursor=self.\u db.execute（'SELECT CONTRACTS.CUSTOMER_NAME，CONTRACTS.CUSTOMER.CITY，CITIES.POPULATION FROM CONTRACTS JOIN CITIES ON CONTRACTS.CUSTOMER_CITY=CITIES.IDENT where{condition}.format（self_table），condition=row['where']）return dict（cursor.fetchall（））抛出错误。format（self_table），condition=row['where']NameError:全局名称“self_table”未定义RM=对象关系映射器；这意味着您不需要再编写普通SQL。请看一看或仅举一个例子。在上面的代码中，您忘记了

self

后面的点（应该是

self.\u table

）。您还将括号再次放错了

self.\u table

。您的错误并不都是python特有的。您必须小心设置括号、大括号、圆点等。

>'update {} set BASE_PRICE = ? where {}'.format(self._table), (row['BASE_PRICE'], >row['where']))
>IndexError: tuple index out of range

    def retrieve(self, key):
        cursor = self._db.execute('select  from {}'.format(self._table))
        return dict(cursor.fetchone())

    def update(self, row):
        self._db.execute(
            'update {} set BASE_PRICE = ? where {}'.format(self._table), 
            (row['BASE_PRICE'], row['where']))
        self._db.commit()

    def disp_rows(self):
        cursor = self._db.execute('select IDENT, CONTRACT_CLASS, BASE_PRICE from {} order 
        by BASE_PRICE'.format(self._table))
        for row in cursor:
            print('  {}: {}: {}'.format(row['IDENT'], row['CONTRACT_CLASS'], 
            row['BASE_PRICE']))

    def __iter__(self):
        cursor = self._db.execute('select * from {} order by  
        BASE_PRICE'.format(self._table))
        for row in cursor:
            yield dict(row)


    def main():
    db_cities = database(filename = 'insurance.sqlite', table = 'CITIES')
    db= database(filename = 'insurance.sqlite', table = 'CONTRACTS')
    db_cars = database(filename = 'insurance.sqlite', table = 'CARS')

    print('Retrieve rows')
    for row in db: print(row)

    print('Update rows')
    db.update({'where': 'CONTRACT_CLASS' >= 10', 'BASE_PRICE'= 1000})
    for row in db: print(row)

    print('Retrieve rows after update')
    for row in db: print(row)

Thanks in advance for your help!