django - How to see if a value or object is in a QuerySet field -

how see if value in queryset?

for example, if have following model:

class userprofile(models.model):     user = models.foreignkey(user, unique=true)     first_name = models.charfield(max_length=50) 

how find out if first_name 'david' contained in queryset? way following:

ld = userprofile.objects.filter(...).values('first_name')     >>> object in ld:     ...     if object['first_name'] =='david':     ...             print true 

or if particular user object instead? 'david' in queryset['first_name'] ? thank you.

simplest way use get method of manager:

try:     foo = foo.objects.get(foo_name='david') except foo.doesnotexist:     print 'nope' except foo.multipleobjectsreturned:     print 'filter better choice here' 

the exists method applicable also, if don't need object:

if foo.objects.filter(foo_color='green').exists():     print 'nice' 

if have object , want determine if contained in queryset:

foo = foo.objects.get(foo_name='david') qs = foo.objects.filter(<criteria>) if foo in qs:     print 'nice again' 

if want use value instead of object:

value = 'david' qs = foo.objects.filter(<criteria>).values_list('foo_name',flat=true) if value in qs:     print 'nice'