django等效于此SQL查询？

Question

I am very new to django and I am tryin to accomplish some repetitive tasks. I was wondering what would be the django equivalent of the following tasks.

1. I want to select all values that fall within a certain date range.

Eg: Let there be a table called exam scores

 User Physics  Chemistry Mathematics Total  Date
 bill    98       94          Pass    284   02/03/2013
 murray  0        89          Fail     89   02/03/2013
 bill    10       20          Pass     90   01/29/2013

Now assume I want to write a django command that obtains user bill's object for all cases where he has passed in mathematics.

here I would write something like

scores = Score.objects.filter(user = "bill", Mathematics = "pass")

The problem with the above code is when i do something like

 for s in scores:
     print "Physics score =", s.Physics

the control never comes to the print statement.

Answer 1

So I think you are asking for something like this

math_scores = Score.objects.filter(user='bill', date__range=(timezone.now() - datetime.timedelta(days=7), timezone.now()).values_list('mathematics', flat=True)

which will give you all math scores for bill in the past week as a list like

[92, 60]

Is this what you are looking to do or did I misunderstand the question?

Answer 2

Given the data and query you show above, there are no elements matching 'bill' and 'pass'. There are elements matching 'bill' and 'Pass', which is a different thing.

I don't understand the relevance of your point about date ranges, though.