python - python中mysql多连接问题

Question

这里我创建了两个到同一个数据库的 MySQL 连接。

当一个连接更新类中存在的数据库时，另一个连接无法获取更改。这是我的代码

tm():处理连接、执行查询和获取数据库概览的数据库类

class ClassB():
    b = None

    def __init__(self):
        self.b = database()

    def get_overview_for_b(self):
        self.b.mark_invalid('9')
        self.b.mark_invalid('8')
        b_str = ''.join(map(str, self.b.get_overview()))
        print("Getting the overview of b" + b_str)


# initializing class B
inside_class_b = ClassB()
# initializing class for A
a = database()

# get database overview for A
astart = a.get_overview()
a_str = ''.join(map(str, astart))
print("Getting the overview of a before testing" + a_str)

# updating database and get database overview for B
inside_class_b.get_overview_for_b()

# get another overview for A
aend = a.get_overview()
a_str = ''.join(map(str, aend))
print("Getting the overview of a after testing" + a_str)

# The final overview of both A and B should be same, but isn't

实际输出

Getting the overview of a before testing('PENDING', 2)
Getting the overview of b('INVALID', 2)
Getting the overview of a after testing('PENDING', 2)

预期输出

Getting the overview of a before testing('PENDING', 2)
Getting the overview of b('INVALID', 2)
Getting the overview of a after testing('INVALID', 2)

虽然我刚刚尝试过，但如果我使用“a”来更新“b”，则会得到更新后的值。

class ClassB():
    b = None

    def __init__(self):
        self.b = database()

    def get_overview_for_b(self):
        b_str = ''.join(map(str, self.b.get_overview()))
        print("Getting the overview of b" + b_str)


# initializing class B
inside_class_b = ClassB()
# initializing class for A
a = database()

# get database overview for A
astart = a.get_overview()
a_str = ''.join(map(str, astart))
print("Getting the overview of a before testing" + a_str)

# updating using 'a'
a.mark_invalid('9')
a.mark_invalid('8')

# get database overview for B
inside_class_b.get_overview_for_b()

# get another overview for A
aend = a.get_overview()
a_str = ''.join(map(str, aend))
print("Getting the overview of a after testing" + a_str)

预期输出和实际输出相同

Getting the overview of a before testing('PENDING', 2)
Getting the overview of b('INVALID', 2)
Getting the overview of a after testing('INVALID', 2)

编辑 下面是我使用的execute函数无效。这使用了一个公共(public)连接，每次都检查 None 条件。

    def execute(self, statement, attributes):
        """
            Execute a query for the database
            :arg:
                statement - Statement to be executed.
                attributes - Attributes supporting the statement.
        """
        if self._db_connection is None:
            self.connect()
        cursor = self._db_connection.cursor()
        cursor.execute(statement, attributes)
        self._db_connection.commit()
        t = cursor.rowcount
        cursor.close()
        del cursor
        return t

Answer 1

在 get_overview() 中没有提交命令。添加 connection.commit() 后，代码按预期工作。

问题已解决。 感谢所有帮助过我的人。