The SearchQuerySet class is designed to make performing a search and iterating over its results easy and consistent. For those familiar with Django’s ORM QuerySet, much of the SearchQuerySet API should feel familiar.
A couple reasons to follow (at least in part) the QuerySet API:
And from a high-level perspective, QuerySet and SearchQuerySet do very similar things: given certain criteria, provide a set of results. Both are powered by multiple backends, both are abstractions on top of the way a query is performed.
For the impatient:
from haystack.query import SearchQuerySet
all_results = SearchQuerySet().all()
hello_results = SearchQuerySet().filter(content='hello')
hello_world_results = SearchQuerySet().filter(content='hello world')
unfriendly_results = SearchQuerySet().exclude(content='hello').filter(content='world')
recent_results = SearchQuerySet().order_by('-pub_date')[:5]
By default, SearchQuerySet provide the documented functionality. You can extend with your own behavior by simply subclassing from SearchQuerySet and adding what you need, then using your subclass in place of SearchQuerySet.
Most methods in SearchQuerySet “chain” in a similar fashion to QuerySet. Additionally, like QuerySet, SearchQuerySet is lazy (meaning it evaluates the query as late as possible). So the following is valid:
from haystack.query import SearchQuerySet
results = SearchQuerySet().exclude(content='hello').filter(content='world').order_by('-pub_date').boost('title', 0.5)[10:20]
Searching your document fields is a very common activity. To help mitigate possible differences in SearchField names (and to help the backends deal with search queries that inspect the main corpus), there is a special field called content. You may use this in any place that other fields names would work (e.g. filter, exclude, etc.) to indicate you simply want to search the main documents.
For example:
from haystack.query import SearchQuerySet
# This searches whatever fields were marked ``document=True``.
results = SearchQuerySet().exclude(content='hello')
This special pseudo-field works best with the exact lookup and may yield strange or unexpected results with the other lookups.
The primary interface to search in Haystack is through the SearchQuerySet object. It provides a clean, programmatic, portable API to the search backend. Many aspects are also “chainable”, meaning you can call methods one after another, each applying their changes to the previous SearchQuerySet and further narrowing the search.
All SearchQuerySet objects implement a list-like interface, meaning you can perform actions like getting the length of the results, accessing a result at an offset or even slicing the result list.
Returns all results for the query. This is largely a no-op (returns an identical copy) but useful for denoting exactly what behavior is going on.
Returns an EmptySearchQuerySet that behaves like a SearchQuerySet but always yields no results.
Filters the search by looking for (and including) certain attributes.
The lookup parameters (**kwargs) should follow the Field lookups below. If you specify more than one pair, they will be joined in the query according to the HAYSTACK_DEFAULT_OPERATOR setting (defaults to AND).
If a string with one or more spaces in it is specified as the value, an exact match will be performed on that phrase.
Warning
Any data you pass to filter is passed along unescaped. If you don’t trust the data you’re passing along, you should either use auto_query or use the clean method on your SearchQuery to sanitize the data.
Example:
SearchQuerySet().filter(content='foo')
SearchQuerySet().filter(content='foo', pub_date__lte=datetime.date(2008, 1, 1))
# Identical to the previous example.
SearchQuerySet().filter(content='foo').filter(pub_date__lte=datetime.date(2008, 1, 1))
# To escape user data:
sqs = SearchQuerySet()
sqs = sqs.filter(title=sqs.query.clean(user_query))
Narrows the search by ensuring certain attributes are not included.
Warning
Any data you pass to exclude is passed along unescaped. If you don’t trust the data you’re passing along, you should either use auto_query or use the clean method on your SearchQuery to sanitize the data.
Example:
SearchQuerySet().exclude(content='foo')
Narrows the search by looking for (and including) certain attributes. Join behavior in the query is forced to be AND. Used primarily by the filter method.
Narrows the search by looking for (and including) certain attributes. Join behavior in the query is forced to be OR. Used primarily by the filter method.
Alters the order in which the results should appear. Arguments should be strings that map to the attributes/fields within the index. You may specify multiple fields by comma separating them:
SearchQuerySet().filter(content='foo').order_by('author', 'pub_date')
Default behavior is ascending order. To specify descending order, prepend the string with a -:
SearchQuerySet().filter(content='foo').order_by('-pub_date')
Note
In general, ordering is locale-specific. Haystack makes no effort to try to reconcile differences between characters from different languages. This means that accented characters will sort closely with the same character and NOT necessarily close to the unaccented form of the character.
If you want this kind of behavior, you should override the prepare_FOO methods on your SearchIndex objects to transliterate the characters as you see fit.
If supported by the backend, the SearchResult objects returned will include a highlighted version of the result:
sqs = SearchQuerySet().filter(content='foo').highlight()
result = sqs[0]
result.highlighted['text'][0] # u'Two computer scientists walk into a bar. The bartender says "<em>Foo</em>!".'
Accepts an arbitrary number of Model classes to include in the search. This will narrow the search results to only include results from the models specified.
Example:
SearchQuerySet().filter(content='foo').models(BlogEntry, Comment)
Allows specifying a different class to use for results.
Overrides any previous usages. If None is provided, Haystack will revert back to the default SearchResult object.
Example:
SearchQuerySet().result_class(CustomResult)
Boosts a certain term of the query. You provide the term to be boosted and the value is the amount to boost it by. Boost amounts may be either an integer or a float.
Example:
SearchQuerySet().filter(content='foo').boost('bar', 1.5)
Adds faceting to a query for the provided field. You provide the field (from one of the SearchIndex classes) you like to facet on.
In the search results you get back, facet counts will be populated in the SearchResult object. You can access them via the facet_counts method.
Example:
# Count document hits for each author within the index.
SearchQuerySet().filter(content='foo').facet('author')
Adds faceting to a query for the provided field by date. You provide the field (from one of the SearchIndex classes) you like to facet on, a start_date (either datetime.datetime or datetime.date), an end_date and the amount of time between gaps as gap_by (one of 'year', 'month', 'day', 'hour', 'minute' or 'second').
You can also optionally provide a gap_amount to specify a different increment than 1. For example, specifying gaps by week (every seven days) would would be gap_by='day', gap_amount=7).
In the search results you get back, facet counts will be populated in the SearchResult object. You can access them via the facet_counts method.
Example:
# Count document hits for each day between 2009-06-07 to 2009-07-07 within the index.
SearchQuerySet().filter(content='foo').date_facet('pub_date', start_date=datetime.date(2009, 6, 7), end_date=datetime.date(2009, 7, 7), gap_by='day')
Adds faceting to a query for the provided field with a custom query. You provide the field (from one of the SearchIndex classes) you like to facet on and the backend-specific query (as a string) you’d like to execute.
Please note that this is NOT portable between backends. The syntax is entirely dependent on the backend. No validation/cleansing is performed and it is up to the developer to ensure the query’s syntax is correct.
In the search results you get back, facet counts will be populated in the SearchResult object. You can access them via the facet_counts method.
Example:
# Count document hits for authors that start with 'jo' within the index.
SearchQuerySet().filter(content='foo').query_facet('author', 'jo*')
Pulls a subset of documents from the search engine to search within. This is for advanced usage, especially useful when faceting.
Example:
# Search, from recipes containing 'blend', for recipes containing 'banana'.
SearchQuerySet().narrow('blend').filter(content='banana')
# Using a fielded search where the recipe's title contains 'smoothie', find all recipes published before 2009.
SearchQuerySet().narrow('title:smoothie').filter(pub_date__lte=datetime.datetime(2009, 1, 1))
By using narrow, you can create drill-down interfaces for faceting by applying narrow calls for each facet that gets selected.
This method is different from SearchQuerySet.filter() in that it does not affect the query sent to the engine. It pre-limits the document set being searched. Generally speaking, if you’re in doubt of whether to use filter or narrow, use filter.
Note
This method is, generally speaking, not necessarily portable between backends. The syntax is entirely dependent on the backend, though most backends have a similar syntax for basic fielded queries. No validation/cleansing is performed and it is up to the developer to ensure the query’s syntax is correct.
Passes a raw query directly to the backend. This is for advanced usage, where the desired query can not be expressed via SearchQuerySet.
Warning
Unlike many of the other methods on SearchQuerySet, this method does not chain by default (depends on the backend). Any other attributes on the SearchQuerySet are ignored and only the provided query is run.
Example:
# In the case of Solr... (this example could be expressed with SearchQuerySet)
SearchQuerySet().raw_search('django_ct:blog.blogentry "However, it is"')
Please note that this is NOT portable between backends. The syntax is entirely dependent on the backend. No validation/cleansing is performed and it is up to the developer to ensure the query’s syntax is correct.
Further, the use of **kwargs are completely undocumented intentionally. If a third-party backend can implement special features beyond what’s present, it should use those **kwargs for passing that information. Developers should be careful to make sure there are no conflicts with the backend’s search method, as that is called directly.
Efficiently populates the objects in the search results. Without using this method, DB lookups are done on a per-object basis, resulting in many individual trips to the database. If load_all is used, the SearchQuerySet will group similar objects into a single query, resulting in only as many queries as there are different object types returned.
Example:
SearchQuerySet().filter(content='foo').load_all()
Deprecated for removal before Haystack 1.0-final.
Please see the docs on RelatedSearchQuerySet.
Performs a best guess constructing the search query.
This method is intended for common use directly with a user’s query. It is a shortcut to the other API methods that follows generally established search syntax without requiring each developer to implement their own parser.
It handles exact matches (specified with single or double quotes), negation ( using a - immediately before the term) and joining remaining terms with the operator specified in HAYSTACK_DEFAULT_OPERATOR.
Example:
SearchQuerySet().auto_query('goldfish "old one eye" -tank')
# ... is identical to...
SearchQuerySet().filter(content='old one eye').filter(content='goldfish').exclude(content='tank')
This method is somewhat naive but works well enough for simple, common cases.
A shortcut method to perform an autocomplete search.
Must be run against fields that are either NgramField or EdgeNgramField.
Example:
SearchQuerySet().autocomplete(title_autocomplete='gol')
Finds similar results to the object passed in.
You should pass in an instance of a model (for example, one fetched via a get in Django’s ORM). This will execute a query on the backend that searches for similar results. The instance you pass in should be an indexed object. Previously called methods will have an effect on the provided results.
It will evaluate its own backend-specific query and populate the SearchQuerySet` in the same manner as other methods.
Example:
entry = Entry.objects.get(slug='haystack-one-oh-released')
mlt = SearchQuerySet().more_like_this(entry)
mlt.count() # 5
mlt[0].object.title # "Haystack Beta 1 Released"
# ...or...
mlt = SearchQuerySet().filter(public=True).exclude(pub_date__lte=datetime.date(2009, 7, 21)).more_like_this(entry)
mlt.count() # 2
mlt[0].object.title # "Haystack Beta 1 Released"
Returns the total number of matching results.
This returns an integer count of the total number of results the search backend found that matched. This method causes the query to evaluate and run the search.
Example:
SearchQuerySet().filter(content='foo').count()
Returns the best/top search result that matches the query.
This method causes the query to evaluate and run the search. This method returns a SearchResult object that is the best match the search backend found:
foo = SearchQuerySet().filter(content='foo').best_match()
foo.id # Something like 5.
# Identical to:
foo = SearchQuerySet().filter(content='foo')[0]
Returns the most recent search result that matches the query.
This method causes the query to evaluate and run the search. This method returns a SearchResult object that is the most recent match the search backend found:
foo = SearchQuerySet().filter(content='foo').latest('pub_date')
foo.id # Something like 3.
# Identical to:
foo = SearchQuerySet().filter(content='foo').order_by('-pub_date')[0]
Returns the facet counts found by the query. This will cause the query to execute and should generally be used when presenting the data (template-level).
You receive back a dictionary with three keys: fields, dates and queries. Each contains the facet counts for whatever facets you specified within your SearchQuerySet.
Note
The resulting dictionary may change before 1.0 release. It’s fairly backend-specific at the time of writing. Standardizing is waiting on implementing other backends that support faceting and ensuring that the results presented will meet their needs as well.
Example:
# Count document hits for each author.
sqs = SearchQuerySet().filter(content='foo').facet('author')
sqs.facet_counts()
# Gives the following response:
# {
# 'dates': {},
# 'fields': {
# 'author': [
# ('john', 4),
# ('daniel', 2),
# ('sally', 1),
# ('terry', 1),
# ],
# },
# 'queries': {}
# }
Returns the spelling suggestion found by the query.
To work, you must set settings.HAYSTACK_INCLUDE_SPELLING (see Haystack Settings) to True. Otherwise, None will be returned.
This method causes the query to evaluate and run the search if it hasn’t already run. Search results will be populated as normal but with an additional spelling suggestion. Note that this does NOT run the revised query, only suggests improvements.
If provided, the optional argument to this method lets you specify an alternate query for the spelling suggestion to be run on. This is useful for passing along a raw user-provided query, especially when there are many methods chained on the SearchQuerySet.
Example:
sqs = SearchQuerySet().auto_query('mor exmples')
sqs.spelling_suggestion() # u'more examples'
# ...or...
suggestion = SearchQuerySet().spelling_suggestion('moar exmples')
suggestion # u'more examples'
Returns a list of dictionaries, each containing the key/value pairs for the result, exactly like Django’s ValuesQuerySet.
This method causes the query to evaluate and run the search if it hasn’t already run.
You must provide a list of one or more fields as arguments. These fields will be the ones included in the individual results.
Example:
sqs = SearchQuerySet().auto_query('banana').values('title', 'description')
Returns a list of field values as tuples, exactly like Django’s ValuesListQuerySet.
This method causes the query to evaluate and run the search if it hasn’t already run.
You must provide a list of one or more fields as arguments. These fields will be the ones included in the individual results.
You may optionally also provide a flat=True kwarg, which in the case of a single field being provided, will return a flat list of that field rather than a list of tuples.
Example:
sqs = SearchQuerySet().auto_query('banana').values_list('title', 'description')
# ...or just the titles as a flat list...
sqs = SearchQuerySet().auto_query('banana').values_list('title', flat=True)
The following lookup types are supported:
These options are similar in function to the way Django’s lookup types work. The actual behavior of these lookups is backend-specific.
Warning
The startswith filter is strongly affected by the other ways the engine parses data, especially in regards to stemming (see Glossary). This can mean that if the query ends in a vowel or a plural form, it may get stemmed before being evaluated.
This is both backend-specific and yet fairly consistent between engines, and may be the cause of sometimes unexpected results.
Example:
SearchQuerySet().filter(content='foo')
# Identical to:
SearchQuerySet().filter(content__exact='foo')
# Other usages look like:
SearchQuerySet().filter(pub_date__gte=datetime.date(2008, 1, 1), pub_date__lt=datetime.date(2009, 1, 1))
SearchQuerySet().filter(author__in=['daniel', 'john', 'jane'])
SearchQuerySet().filter(view_count__range=[3, 5])
Also included in Haystack is an EmptySearchQuerySet class. It behaves just like SearchQuerySet but will always return zero results. This is useful for places where you want no query to occur or results to be returned.