Django icontains behaves differently on web vs shell - django-views

Question

Edit: I also tried iregex and found that it behaves in the same manner as icontains below.
form_search = FormTest.objects.filter(name__iregex=rf"{new_data}")
I'm running in to a problem where an identical query behaves differently if it is run in project vs when it is run in that project's shell.
I created a sample table in my project's database (FormTest). The FormTest table contains a field called "name" where I added values such as "Mike" "Mike Smith" "John" "Jonathan", etc.
I then created a simple form to search for names in the table using icontains:
if request.method == 'POST':
input_form = FormClassSearch(request.POST)
if input_form.is_valid():
new_data = input_form.cleaned_data
new_data = str(new_data['name'])
form_search = FormTest.objects.filter(name__icontains=new_data)
form_search_q =\
FormTest.objects.filter(name__icontains=new_data).query
When I use the form to search for "Mike" it returns "Mike" and "Mike Smith". However, if I search for "Mike Smith" it returns nothing. A stranger problem exists when I try to find "Jonathan". If I search for "Jo" it returns both "John" and "Jonathan". If I try to search for "Jon" "Jona" ... "Jonathan" it returns nothing.
To make sure I was writing the query correctly, I fired up the manage.py shell:
>>> c = 'mike smith'
>>> print(c)
mike smith
>>> a = FormTest.objects.filter(name__icontains=c)
>>> a.exists()
True
>>> len(a)
1
>>> for item in a:
... print(item.name)
...
Mike Smith
>>> b = FormTest.objects.filter(name__icontains=c).query
>>> print(b)
SELECT "workout_formtest"."id", "workout_formtest"."name",
"workout_formtest"."dob", "workout_formtest"."number", "workout_formtest"."number2"
FROM "workout_formtest" WHERE UPPER("workout_formtest"."name"::text)
LIKE UPPER(%mike smith%)
I confirmed that the SQL from .query matches (shell output vs application output).
I also coded the template to print the search term, to make sure the input was being passed correctly.
Anyone have any idea what I'm doing wrong or why the application is not behaving as expected? I only have one database in settings.py - a Postgresql DB. The form I created to ADD data in to the table works perfectly.

Answer 1

Solved:
I don't know the exact cause, but I believe it has to do with the fact that QuerySets are lazy. Originally,the queryset was not evaluated until it was iterated through on the template. My solution is to iterate through the query set in the view, and append the results to a list:
def formsearchpage(request):
...
query_list = []
if request.method == 'POST':
input_form = ClassSearchForm(request.POST)
if input_form.is_valid():
new_data = input_form.cleaned_data
new_data = str(new_data['name'])
form_search = FormTest.objects.filter(name__iregex=rf"{new_data}")
count = len(form_search)
message = "Your input " + new_data
if count == 1:
message = 'One Match Found on ' + new_data
for item in form_search:
query_list.append(item.name)
if count >= 2:
message = 'More than one match found on ' + new_data
for item in form_search:
query_list.append(item.name)
...
The key is:
for item in form_search:
query_list.append(item.name)
query_list is then passed to the template, which displays it:
{% if query_list %}
{% for i in query_list %}
<p>{{ i }}</p>
{% endfor %}
{% endif %}
Now, when I render the template, the loop that iterates through 'query_list' displays the expected data, while the old loop that iterated through the raw QuerySet (the 'form_search' object created in the view) does not.