如何在 Python 中模拟 cx_Oracle 光标

Question

我在 class 中有以下两个函数，我需要模拟数据库连接和游标结果。 cx_Oracle.connect 成功修补它按预期工作。但是游标、callfunc、fetch_all 不会被模拟。知道什么是正确的语法吗？

class dbconnect:

    def db_connect(self, connection_details):
        connection = cx_Oracle.connect(user_name,pwd,<connection_string>)
        return connection

    def execute_function(self, sqlFunction, args):
        cursor = self.connection.cursor()
        res=cursor.callfunc(sqlFunction, cursor.var(cx_Oracle.CURSOR), args)
        results = {'headers' : [x[0] for x in res.description],
            'data': res.fetchall()
        }
        cursor.close()
        return results

我的模拟代码

with mock.patch('dbconnect.cx_Oracle.connect') as mockOracle:

   result_set = {}
   mockOracle.cursor.callfunc.fetch_all = result_set

Answer 1

实际上您根本不需要 "mock" 建立连接和光标！您可以自己简单地子类化连接和游标，如下所示：

class MyConnection(cx_Oracle.Connection):

    def cursor(self, scrollable=False):
        return MyCursor(self, scrollable)

class MyCursor(cx_Oracle.Cursor):

    def execute(self, sql, args):
        result = super(MyConnection, self).execute(sql, args)
        print("My mock execute...")
        return result

我不确定这是否是您的意图，或者您是否知道这种可能性。有了它，您可以添加新功能，也可以覆盖或扩展现有功能。

Answer 2

我有一个类似的问题，所以我用我创建的 class 修补了 cx_Oracle.connect() 方法，所以它既可以在上下文管理器中工作，也可以在 returns 模拟游标中工作。游标应该适用于 fetchmany 和 fetchall

import cx_Oracle

class MockCursor:
    def __init__(self, *args, **kwargs):
        self.fetched = False
        self.rows = None
        self.description = [("id",), ("name",)]

    def callfunc(self, *args):
        return self

    @staticmethod
    def var(*args):
        pass

    @staticmethod
    def execute(query):
        pass

    @staticmethod
    def close():
        pass

    def fetchmany(self, *args):
        if not self.fetched:
            self.rows = self.fetch_rows()
            self.fetched = True

        return next(self.rows)

    @staticmethod
    def fetchall():
        return [
            (1, "TEST A"),
            (2, "TEST B"),
            (3, "TEST C"),
        ]


    def fetch_rows(self):
        yield self.fetchall()
        yield None


class MockConnect:
    def __enter__(self, *args, **kwargs):
        return self

    def __exit__(self, type, value, traceback):
        pass

    @staticmethod
    def cursor():
        return MockCursor()

    @staticmethod
    def close():
        pass
 

@mock.patch.object(cx_Oracle, "connect")
def test_foo(mock_connect):
    mock_connect.return_value = MockConnect()

如何在 Python 中模拟 cx_Oracle 光标

How to mock cx_Oracle cursor in Python

python

mocking

patch

python-unittest

cx-oracle