为什么在try块中获得MultipleObjectsReturned错误？

Question

Any help on this one would great. I'm using python 2.7 and django 1.2 Here's my code:

for save in saved: #list to iterate
    try:
        sect = obj.get(name=save) #obj is a RelatedManager
    except: #if two sections have the same name
        sect = obj.filter(name=save)
    else:
        #finish my code

I get a MultipleObjectsReturned error everytime when it hits the get() statement. I'm no expert at python so I imagine I missed something simple.

Answer 1

Two objects have the name values equal to the value of save

When using get and there are more than 1 row returned it raises MultipleObjectsReturned

I think you should catch this explicitly because your except as it stands will also catch DoesNotExist errors (and all oteher errors)

    from django.core.exceptions import MultipleObjectsReturned

    try:
        sect = obj.get(name=save) #obj is a RelatedManager
    except MultipleObjectsReturned: #if two sections have the same name
        sect = obj.filter(name=save)[0]
    else:
        #finish my code

Answer 2

Because you have more than 1 record in the database with name=save. Use filter() and get the one at index 0 if you want just one or properly handle that case separately .