Django 1.4 - assertQuerysetEqual - 如何使用方法

Question

我想知道TestCase.assertQuerysetEqual方法是如何工作的.我以不同的方式尝试了它,每个都引导我另一个错误信息.

#create a backup of all records in the tree
tree_record_backup = list(Tree.objects.all())

#do some updates on another table, which should not affect the tree table if everything goes wrong

#check if list of tree records did not changed
tree_record_qs = Tree.objects.all()
#Number1:
self.assertQuerysetEqual(tree_record_qs,[repr(tree_record_backup)])
#Number2:
self.assertQuerysetEqual(tree_record_qs,tree_record_backup)

Number1的错误消息:

First list contains 21 additional elements.
First extra element 1:
node.pk: 2 - node: node2 - pk: 2 - level: 0 - ancestor: 2

第2个错误消息:

AssertionError: Lists differ: ['<Tree: node.pk: 1 - node: ro... != [<Tree: node.pk: 1 - node: roo...

First differing element 0:
<Tree: node.pk: 1 - node: root - pk: 1 - level: 0 - ancestor: 1>
node.pk: 1 - node: root - pk: 1 - level: 0 - ancestor: 1

感谢您提示如何正确使用assertQuerysetEqual方法.

Answer 1

assertQuerysetEqual需要queryset,一个值列表和一个transform可调用这就是所谓的查询集将其转换成东西比得上值的列表.默认情况下,这个可调用的是repr.这有点令人恼火,因为它实际上并不比较两个查询集,但大多数情况下的简单修复是map(repr, your_second_queryset)用于值列表.自1.3版以来,这在django中有记载.

Answer 2

试试这个:

self.assertQuerysetEqual(
    tree_record_qs,
    [repr(r) for r in tree_record_backup]
)

它有点奇怪而且没有记录; 但是,这应该对你有用.