Python TypeError 中的 Mysql.connector

Question

我已经定义了一个数据库类如下：-

class Database(object):
    """ Implements all interactions with the DB. """

    def __init__(self, id_a, id_b, config):
        self.config = config
        self.id_a = id_a
        self.id_b = id_b
        self.db_connection = None
        self.cursor = None
        self.__init_db(config)

    def __init_db(self, config):
        """
        Initializes the MySQL Connector using the settings
        specified in the system configuration.

        """
        self.db_connection = mysql.connector.connect(user=config['database_user'],
                                                     password=config['database_password'],
                                                     host=config['database_host'],
                                                     database=config['database_name'])
        self.cursor = self.db_connection.cursor(dictionary=True,buffered=True)
        self.cursor.execute('SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;')

现在，当我定义以下函数以返回从 Mysql 数据库中获取的值时，我得到一个错误

    def get_func(self):
        sql = "SELECT c_id FROM table \
        WHERE id_a = {} ".format(self.id_a)
        self.cursor.execute(sql)
        rows = self.cursor.fetchone()
        if rows:
            for row in rows:
                ls1 = row['id_number']
            return ls1



    ls1 = row['id_number']
TypeError: string indices must be integers

Answer 1

在row['id_number'] row 中不是dict 类型，而是tuple 类型。

for row in rows:
    ls1 = row['id_number'] # error

你的情况是这样的

words = ('foo',)
words['id_number'] # error we need to pass only `int`

words[0] # right
# Output
# foo

row 也是单身，您不需要使用 for loop statment 只需 row[0]

row = self.cursor.fetchone()
if row:
    return row[0]