Multiple querystring parameters

Question

I've created this simple search function:

def search(request):
    if "q" in request.GET:
        querystring = request.GET.get("q")
        print(querystring)
        if len(querystring) == 0:
            return redirect("/search/")
        posts = Blog.objects.filter(title__icontains=querystring | tagline__icontains=querystring | contents__icontains=querystring)
        context= {"posts": posts}
        return render(request, "kernel/search.html", context)
    else:
        return render(request, "kernel/search.html")

When I use only one condition, for example:

 posts = Blog.objects.filter(title__icontains=querystring) 

it's shown me the correct results. But when I use multiple parameters I have SyntaxError: invalid syntax.

I was sure the query corresponded to:

SELECT * FROM Post WHERE "title" is "key_search" or "tagline" is "key_search" or "contents" is "key_search"

How I can resolve?

Answer 1

The above is incorrect Python syntax, you can not put operators between named parameters.

Django however has Q objects [Django-doc] to express "conditions", so you can wrap the conditions in Q objects, and use the | operator to express a logical or, like:

from django.db.models import Q

posts = Blog.objects.filter(
    Q(title__icontains=querystring) |
    Q(tagline__icontains=querystring) |
    Q(contents__icontains=querystring)
)

This will result in a query that looks, more or less, like:

SELECT *
FROM Post
WHERE "title" LIKE "%key_search%"
   OR "tagline" LIKE "%key_search%"
   OR "contents" LIKE "%key_search%"