Django QuerySet
Django QuerySet
A QuerySet is a collection of data from a database.
A QuerySet is built up as a list of objects.
QuerySets makes it easier to get the data you actually need, by allowing you to filter and order the data at an early stage.
In this tutorial we will be querying data from the Member table.
Member:
| id | firstname | lastname | phone | joined_date |
|---|---|---|---|---|
| 1 | Emil | Refsnes | 5551234 | 2022年01月05日 |
| 2 | Tobias | Refsnes | 5557777 | 2022年04月01日 |
| 3 | Linus | Refsnes | 5554321 | 2021年12月24日 |
| 4 | Lene | Refsnes | 5551234 | 2021年05月01日 |
| 5 | Stalikken | Refsnes | 5559876 | 2022年09月29日 |
Querying Data
In views.py, we have a view for testing called
testing where we will test different queries.
In the example below we use the .all()
method to get all the records and fields of the Member model:
View
views.py:
from django.http import HttpResponse
from django.template import loader
from .models import Member
def testing(request):
mydata = Member.objects.all()
template = loader.get_template('template.html')
context = {
'mymembers': mydata,
}
return HttpResponse(template.render(context, request))The object is placed in a variable called mydata, and is sent to the template
via the context object as
mymembers, and looks like this:
<Member: Member object (1)>,
<Member: Member object (2)>,
<Member: Member object (3)>,
<Member: Member object (4)>,
<Member: Member object (5)>
]>
As you can see, our Member model contains 5 records, and are listed inside
the QuerySet as 5 objects.
In the template you can use the mymembers
object to generate content:
Template
templates/template.html:
<table border='1'>
<tr>
<th>ID</th>
<th>Firstname</th>
<th>Lastname</th>
</tr>
{% for x in mymembers %}
<tr>
<td>{{ x.id }}</td>
<td>{{ x.firstname }}</td>
<td>{{ x.lastname }}</td>
</tr>
{% endfor %}
</table>