DjangoQL
Advanced search language for Django, with auto-completion. Supports logical operators, parenthesis, table joins, and works with any Django model. Tested on Python 2.7, 3.6 - 3.12, Django 1.8 - 5.0. The auto-completion feature has been tested in Chrome, Firefox, Safari, IE9+.
See a video: DjangoQL demo
DjangoQL is used by:
Is your project using DjangoQL? Please submit a PR and let us know!
Contents
- Installation
- Add it to your Django admin
- Using DjangoQL with the standard Django admin search
- Language reference
- DjangoQL Schema
- Custom search fields
- Can I use it outside of Django admin?
- Using completion widget outside of Django admin
Installation
$ pip install djangoql
Add 'djangoql'
to INSTALLED_APPS
in your settings.py
:
INSTALLED_APPS = [
...
'djangoql',
...
]
Add it to your Django admin
Adding DjangoQLSearchMixin
to your model admin will replace the
standard Django search functionality with DjangoQL search. Example:
from django.contrib import admin
from djangoql.admin import DjangoQLSearchMixin
from .models import Book
@admin.register(Book)
class BookAdmin(DjangoQLSearchMixin, admin.ModelAdmin):
pass
Using DjangoQL with the standard Django admin search
DjangoQL will recognize if you have defined search_fields
in your
ModelAdmin class, and doing so will allow you to choose between an
advanced search with DjangoQL and a standard Django search (as specified
by search fields). Example:
@admin.register(Book)
class BookAdmin(DjangoQLSearchMixin, admin.ModelAdmin):
search_fields = ('title', 'author__name')
For the example above, a checkbox that controls search mode will appear
near the search input. If the checkbox is on, then DjanqoQL search is
used. There is also an option that controls if that checkbox is enabled
by default -djangoql_completion_enabled_by_default
(set to True
by
default):
@admin.register(Book)
class BookAdmin(DjangoQLSearchMixin, admin.ModelAdmin):
search_fields = ('title', 'author__name')
djangoql_completion_enabled_by_default = False
If you don\'t want two search modes, simply remove search_fields
from
your ModelAdmin class.
Language reference
DjangoQL is shipped with comprehensive Syntax Help, which can be found in Django admin (see the Syntax Help link in auto-completion popup). Here\'s a quick summary:
DjangoQL\'s syntax resembles Python\'s, with some minor differences. Basically you just reference model fields as you would in Python code, then apply comparison and logical operators and parenthesis. DjangoQL is case-sensitive.
- model fields: exactly as they are defined in Python code. Access
nested properties via
.
, for exampleauthor.last_name
; - strings must be double-quoted. Single quotes are not supported. To
escape a double quote use
\"
; - boolean and null values:
True
,False
,None
. Please note that they can be combined only with equality operators, so you can writepublished = False or date_published = None
, butpublished > False
will cause an error; - logical operators:
and
,or
; - comparison operators:
=
,!=
,<
,<=
,>
,>=
- work as you expect;
- string-specific comparison operators:
startswith
,not startswith
,endswith
,not endswith
- work as you expect. Test whether or not a string contains a substring:~
and!~
(translated into__icontains
under the hood). Example:name endswith "peace" or author.last_name ~ "tolstoy"
; - date-specific comparison operators, compare by date part:
~
and!~
. Example:date_published ~ "2021-11"
- find books published in Nov, 2021; - test a value vs. list:
in
,not in
. Example:pk in (2, 3)
.
DjangoQL Schema
Schema defines limitations - what you can do with a DjangoQL query. If you don\'t specify any schema, DjangoQL will provide a default schema for you. This will walk recursively through all model fields and relations and include everything it finds in the schema, so users would be able to search through everything. Sometimes this is not what you want, either due to DB performance or security concerns. If you\'d like to limit search models or fields, you should define a schema. Here\'s an example:
class UserQLSchema(DjangoQLSchema):
exclude = (Book,)
suggest_options = {
Group: ['name'],
}
def get_fields(self, model):
if model == Group:
return ['name']
return super(UserQLSchema, self).get_fields(model)
@admin.register(User)
class CustomUserAdmin(DjangoQLSearchMixin, UserAdmin):
djangoql_schema = UserQLSchema
In the example above we created a schema that does 3 things:
- excludes the Book model from search via
exclude
option. Instead ofexclude
you may also useinclude
, which limits a search to listed models only; - limits available search fields for Group model to only the
name
field , in the.get_fields()
method; - enables completion options for Group names via
suggest_options
.
An important note about suggest_options
: it looks for the choices
model field parameter first, and if it\'s not specified - it will
synchronously pull all values for given model fields, so you should
avoid large querysets there. If you\'d like to define custom suggestion
options, see below.
Custom search fields
Deeper search customization can be achieved with custom search fields.
Custom search fields can be used to search by annotations, define custom
suggestion options, or define fully custom search logic. In
djangoql.schema
, DjangoQL defines the following base field classes
that you may subclass to define your own behavior:
IntField
FloatField
StrField
BoolField
DateField
DateTimeField
RelationField
Here are examples for common use cases:
Search by queryset annotations:
from djangoql.schema import DjangoQLSchema, IntField
class UserQLSchema(DjangoQLSchema):
def get_fields(self, model):
fields = super(UserQLSchema, self).get_fields(model)
if model == User:
fields += [IntField(name='groups_count')]
return fields
@admin.register(User)
class CustomUserAdmin(DjangoQLSearchMixin, UserAdmin):
djangoql_schema = UserQLSchema
def get_queryset(self, request):
qs = super(CustomUserAdmin, self).get_queryset(request)
return qs.annotate(groups_count=Count('groups'))
Let\'s take a closer look at what\'s happening in the example above.
First, we add groups_count
annotation to the queryset that is used by
Django admin in the CustomUserAdmin.get_queryset()
method. It would
contain the number of groups a user belongs to. As our queryset now
pulls this column, we can filter by it. It just needs to be included in
the schema. In UserQLSchema.get_fields()
we define a custom integer
search field for the User
model. Its name should match the name of the
column in our queryset.
Custom suggestion options
from djangoql.schema import DjangoQLSchema, StrField
class GroupNameField(StrField):
model = Group
name = 'name'
suggest_options = True
def get_options(self, search):
return super(GroupNameField, self)\
.get_options(search)\
.annotate(users_count=Count('user'))\
.order_by('-users_count')
class UserQLSchema(DjangoQLSchema):
def get_fields(self, model):
if model == Group:
return ['id', GroupNameField()]
return super(UserQLSchema, self).get_fields(model)
@admin.register(User)
class CustomUserAdmin(DjangoQLSearchMixin, UserAdmin):
djangoql_schema = UserQLSchema
In this example we\'ve defined a custom GroupNameField that sorts suggestions for group names by popularity (no. of users in a group) instead of default alphabetical sorting.
Custom search lookup
DjangoQL base fields provide two basic methods that you can override to
substitute either search column, search value, or both
-.get_lookup_name()
and .get_lookup_value(value)
:
class UserDateJoinedYear(IntField):
name = 'date_joined_year'
def get_lookup_name(self):
return 'date_joined__year'
class UserQLSchema(DjangoQLSchema):
def get_fields(self, model):
fields = super(UserQLSchema, self).get_fields(model)
if model == User:
fields += [UserDateJoinedYear()]
return fields
@admin.register(User)
class CustomUserAdmin(DjangoQLSearchMixin, UserAdmin):
djangoql_schema = UserQLSchema
In this example we\'ve defined the custom date_joined_year
search
field for users, and used the built-in Django __year
filter option in
.get_lookup_name()
to filter by date year only. Similarly you can use
.get_lookup_value(value)
hook to modify a search value before it\'s
used in the filter.
Fully custom search lookup
.get_lookup_name()
and .get_lookup_value(value)
hooks cover many
simple use cases, but sometimes they\'re not enough and you want a fully
custom search logic. In such cases you can override main .get_lookup()
method of a field. Example below demonstrates User age
search:
from djangoql.schema import DjangoQLSchema, IntField
class UserAgeField(IntField):
"""
Search by given number of full years
"""
model = User
name = 'age'
def get_lookup_name(self):
"""
We'll be doing comparisons vs. this model field
"""
return 'date_joined'
def get_lookup(self, path, operator, value):
"""
The lookup should support with all operators compatible with IntField
"""
if operator == 'in':
result = None
for year in value:
condition = self.get_lookup(path, '=', year)
result = condition if result is None else result | condition
return result
elif operator == 'not in':
result = None
for year in value:
condition = self.get_lookup(path, '!=', year)
result = condition if result is None else result & condition
return result
value = self.get_lookup_value(value)
search_field = '__'.join(path + [self.get_lookup_name()])
year_start = self.years_ago(value + 1)
year_end = self.years_ago(value)
if operator == '=':
return (
Q(**{'%s__gt' % search_field: year_start}) &
Q(**{'%s__lte' % search_field: year_end})
)
elif operator == '!=':
return (
Q(**{'%s__lte' % search_field: year_start}) |
Q(**{'%s__gt' % search_field: year_end})
)
elif operator == '>':
return Q(**{'%s__lt' % search_field: year_start})
elif operator == '>=':
return Q(**{'%s__lte' % search_field: year_end})
elif operator == '<':
return Q(**{'%s__gt' % search_field: year_end})
elif operator == '<=':
return Q(**{'%s__gte' % search_field: year_start})
def years_ago(self, n):
timestamp = now()
try:
return timestamp.replace(year=timestamp.year - n)
except ValueError:
# February 29
return timestamp.replace(month=2, day=28, year=timestamp.year - n)
class UserQLSchema(DjangoQLSchema):
def get_fields(self, model):
fields = super(UserQLSchema, self).get_fields(model)
if model == User:
fields += [UserAgeField()]
return fields
@admin.register(User)
class CustomUserAdmin(DjangoQLSearchMixin, UserAdmin):
djangoql_schema = UserQLSchema
Can I use it outside of Django admin?
Sure. You can add DjangoQL search functionality to any Django model
using DjangoQLQuerySet
:
from django.db import models
from djangoql.queryset import DjangoQLQuerySet
class Book(models.Model):
name = models.CharField(max_length=255)
author = models.ForeignKey('auth.User')
objects = DjangoQLQuerySet.as_manager()
With the example above you can perform a search like this:
qs = Book.objects.djangoql(
'name ~ "war" and author.last_name = "Tolstoy"'
)
It returns a normal queryset, so you can extend it and reuse if necessary. The following code works fine:
print(qs.count())
Alternatively you can add DjangoQL search to any existing queryset, even if it\'s not an instance of DjangoQLQuerySet:
from django.contrib.auth.models import User
from djangoql.queryset import apply_search
qs = User.objects.all()
qs = apply_search(qs, 'groups = None')
print(qs.exists())
Schemas can be specified either as a queryset option, or passed to
.djangoql()
queryset method directly:
class BookQuerySet(DjangoQLQuerySet):
djangoql_schema = BookSchema
class Book(models.Model):
...
objects = BookQuerySet.as_manager()
# Now, Book.objects.djangoql() will use BookSchema by default:
Book.objects.djangoql('name ~ "Peace") # uses BookSchema
# Overriding default queryset schema with AnotherSchema:
Book.objects.djangoql('name ~ "Peace", schema=AnotherSchema)
You can also provide schema as an option for apply_search()
qs = User.objects.all()
qs = apply_search(qs, 'groups = None', schema=CustomSchema)
Using completion widget outside of Django admin
The completion widget is not tightly coupled to Django admin, so you can easily use it outside of the admin if you want. The widget is available on npm as a standalone package. See the source code and the docs in the djangoql-completion repo on GitHub.
The completion widget is also bundled with the djangoql Python package on PyPI. If you\'re not using Webpack or another JavaScript bundler, you can use the pre-built version that ships with the Python package. Here is an example:
Template code, completion_demo.html
:
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>DjangoQL completion demo</title>
<link rel="stylesheet" type="text/css" href="{% static 'djangoql/css/completion.css' %}" />
<script src="{% static 'djangoql/js/completion.js' %}"></script>
</head>
<body>
<form action="" method="get">
<p style="color: red">{{ error }}</p>
<textarea name="q" cols="40" rows="1" autofocus>{{ q }}</textarea>
</form>
<ul>
{% for item in search_results %}
<li>{{ item }}</li>
{% endfor %}
</ul>
<script>
DjangoQL.DOMReady(function () {
new DjangoQL({
// either JS object with a result of DjangoQLSchema(MyModel).as_dict(),
// or an URL from which this information could be loaded asynchronously
introspections: {{ introspections|safe }},
// css selector for query input or HTMLElement object.
// It should be a textarea
selector: 'textarea[name=q]',
// optional, you can provide URL for Syntax Help link here.
// If not specified, Syntax Help link will be hidden.
syntaxHelp: null,
// optional, enable textarea auto-resize feature. If enabled,
// textarea will automatically grow its height when entered text
// doesn't fit, and shrink back when text is removed. The purpose
// of this is to see full search query without scrolling, could be
// helpful for really long queries.
autoResize: true
});
});
</script>
</body>
</html>
And in your views.py
:
import json
from django.contrib.auth.models import Group, User
from django.shortcuts import render_to_response
from django.views.decorators.http import require_GET
from djangoql.exceptions import DjangoQLError
from djangoql.queryset import apply_search
from djangoql.schema import DjangoQLSchema
from djangoql.serializers import DjangoQLSchemaSerializer
class UserQLSchema(DjangoQLSchema):
include = (User, Group)
suggest_options = {
Group: ['name'],
}
@require_GET
def completion_demo(request):
q = request.GET.get('q', '')
error = ''
query = User.objects.all().order_by('username')
if q:
try:
query = apply_search(query, q, schema=UserQLSchema)
except DjangoQLError as e:
query = query.none()
error = str(e)
# You may want to use SuggestionsAPISerializer and an additional API
# endpoint (see in djangoql.views) for asynchronous suggestions loading
introspections = DjangoQLSchemaSerializer().serialize(
UserQLSchema(query.model),
)
return render_to_response('completion_demo.html', {
'q': q,
'error': error,
'search_results': query,
'introspections': json.dumps(introspections),
})
License
MIT