Trying to get some movies and their genres but leave out any records that contain the genre "Thriller" in the array of genres.
How do I not only ignore the genre key itself for "Thriller", but squelch that entire movie result? With my current query, Thriller is removed from the array of genres, but the parent object (film) is still displayed.
Here's my current workup in the query editor:
http://tinyurl.com/d2g54lj
[{
'type':'/film/film',
'limit':5,
'name':null,
'/film/film/genre': [],
'/film/film/genre!=': "Thriller",
}]
The answer provided is correct, but changes some other stuff in the query too. Here's the direct equivalent to the original query:
[{
"type": "/film/film",
"limit": 5,
"name": null,
"genre": [],
"x:genre": {"name":"Thriller",
"optional":"forbidden"},
}]
The important part is the "optional":"forbidden". The default property used is "name", but we need to specify it explicitly when we use a subclause (to allow us to specify the "optional" keyword). Using ids instead of names, as #kook did, is actually more reliable, so that's an improvement, but I wanted people to be able to see the minimum necessary to fix the broken query.
We can abbreviate the property name to "genre" from "/film/film/genre" since "type":"/film/film" is included (we also never need to use /type/object for properties like /type/object/name).
Answering my own question.
So the trick is to not use the != (but not) operator, but to actually flip it on its head and use the "|=" (one of) operator with 'forbid', like so:
[{
'type':'/film/film',
'limit':5,
'name':null,
'/film/film/genre': [{
"id": null,
"optional": true
}],
"forbid:/film/film/genre": {
"id|=": [
"/en/thriller",
"/en/slapstick"
],
"optional": "forbidden"
}
}]
Thanks to the following post:
Freebase query - exclusion of certain values
Related
My current query is this:
[{
"type": "/people/person",
"also:type": "/film/actor",
"name": "Chuck Norris",
"/imdb/topic/name_id": null,
"date_of_birth": null,
"/film/actor/film": [{
"film": [{
"name": null,
"imdb_id": []
}]
}]
}]
And this works fine for actors. But I want to return films, given a name or IMDB Name ID etc., for anyone who has worked in films. So directors, products, writers etc.
To do this though, requires lots of different types, like: executive_produced_by, produced_by, directed_by etc.
At the moment, if I pass in Mike Newell, I get no results, as he isn't an actor, but a director among other things.
Any ideas as to how to do this in a single query? I am essentially looking for optional types. e.g. find Mike Newell in /film/actors or /film/directed_by etc.
What documentation have you consulted so far? You can use the |= operator to specify multiple IDs, types, etc. You can use the optional: true clause to make a value optional for a property (otherwise, it'll exclude entities which don't have a value for that property).
What have you tried so far and found lacking?
I'm wondering if it is possible to get all info about a specific date from Freebase.
I can easily retrieve info about a date giving a specific topic, for example, to grab all persons of interest who were born on a specific date:
[{
"type":"/people/person",
"limit":1000,
"sort":"name",
"name":null,
"guid":null,
"timestamp":null,
"/people/person/date_of_birth":"1955-02-24"
}]
Is it possible to grab all types? I'm after things like people born on that date (which I have), major events (start of a war, assassination of a person of interest, etc), and so on.
Essentially I want to match all fields that are dates and return the full information about that entry, regardless of type.
Reflection is what you need here:
[{
"/type/reflect/any_value": [{
"type": "/type/datetime",
"value": "1955-02-24",
"link": {
"source": {
"id": null
},
"master_property": null
}
}]
}]
A couple of notes on that: the MQL manual I've linked to is somewhat bitrotted in its details but is still the best documentation that exists on MQL. Secondly, there's what I'm pretty sure is in MQL bug if you use "*": null or more specifically "target_value": null in the link clause above which makes it ignore the outer value you specified... so don't do that :-)
Let's say I want to get all movies in which at least two (different) actors called "John" played:
Example query:
[{
"type":"/film/film",
"name":null,
"limit":10,
"/film/film/initial_release_date":"2005"
"starring":[{
"a:actor": [{
"type": "/film/actor",
"name": null,
"name~=": "John",
}],
"b:actor": [{
"type": "/film/actor",
"name": null,
"name~=": "John",
}]
}]
}]
If you run the example query, you will see that it will list movies with only one "John" in them. How can I fix my query to exclude these results with duplicated children?
In general, you'll have to do the filtering client-side; queries in MQL are "tree-like" in that one part of the query can't refer to another part rather than being a generic graph.
In this case, you could look for films which have more than one "John" acting in them; however, MQL doesn't allow you to filter on a derived property like "count", so the best you can do is to reverse sort based on the count and then just stop processing as soon as you hit the first entry with "count": 1. However, that query times out if you remove the fixed 1935 release date (sorting in MQL kills performance), so you're probably stuck with just simple client-side filtering.
What would be the MQL query if I want to search for a property that has a particular string either in its name or the actual link path. For name, I was able to put a ~= matching on the name property, but not in the link path. I tried to use the ~= in the id, but it says we cannot do matching in the id.
[{
"/type/object/id": "wikipedia",
"name~=": "wikipedia",
"/type/object/type": "/type/property",
"/type/object/name": null
"limit": 200
}]
Is there a way to also search for strings in the id ?
A couple of things:
the ~= operator works on a whole word basis, so if you want to find the string "wikipedia" in all contexts, you'll want to use "*wikipedia*"
IDs aren't stored with fully formed paths, instead they're a sequence of keys in their respective namespaces (think filenames in directories)
You'll need two separate queries to match both the properties and their containing domains since you can't do unions like that in MQL.
For properties who's names contain wikipedia:
[{
"type": "/type/property",
"name~=" : "*wikipedia*",
"name": null,
"id":null,
"limit": 200
}]
and for properties which belong to types who's IDs contain wikipedia:
[{
"type": "/type/property",
"name": null,
"id":null,
"schema" : {"key":{"namespace":{"name~=":"*wikipedia*"}},"id":null},
"limit": 200
}]
That second query may need a little refinement, but it should give you the basic idea.
Can get all triples with value null in specific field?
All people with date_of_birth equal null?
[
"type": "/people/person",
"date_of_birth":null,
"name":null
]
You need to use "optional":"forbidden" directive:
[{
"type": "/people/person",
"date_of_birth": {
"value": null,
"optional": "forbidden"
},
"name": null,
"id": null
}]
(I added "id":null so that the Query Editor gives clickable links)
Note that query has a default "limit":100, if you want more results then add an explicit limit clause. If that times out, then you'll need to use a MQL cursor.
If you need to deal with lots of results, the undocumented envelope parameter "page" provides more flexibility than "cursor", allowing you to move forward, back, or access a page at random, as opposed to just going forward like you can with the cursor.
The "optional": "forbidden" clause is the key to lots of useful queries. The "!everything" == "nothing" equivalency is just one of the most common ones.
Tom