Filter Documents
How to write filters in WOQL
To use this How-To, first clone the Star Wars demo into your team on TerminusCMS. You will then have full access to the data needed for this tutorial
Since WOQL is a datalog, filters are just part of the query. You can express negative information, or constraints on the variables in order to get a restriction down to the things you want.
For instance, we can write the following query in the query panel for the Star Wars demo:
let v = Vars("person","person_name","vehicle","vehicle_name");
limit(10)
.select(v.person_name, v.vehicle_name)
.and(triple(v.vehicle, "pilot", v.person),
triple(v.vehicle, "label", v.vehicle_name),
triple(v.person, "label", v.person_name))
This results in:
[ {"person_name": {"@type":"xsd:string", "@value":"Chewbacca"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Han Solo"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Lando Calrissian"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Nien Nunb"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Luke Skywalker"},
"vehicle_name": {"@type":"xsd:string", "@value":"X-wing"}},
{"person_name": {"@type":"xsd:string", "@value":"Wedge Antilles"},
"vehicle_name": {"@type":"xsd:string", "@value":"X-wing"}},
{"person_name": {"@type":"xsd:string", "@value":"Jek Tono Porkins"},
"vehicle_name": {"@type":"xsd:string", "@value":"X-wing"}},
{"person_name": {"@type":"xsd:string", "@value":"Biggs Darklighter"},
"vehicle_name": {"@type":"xsd:string", "@value":"X-wing"}},
{"person_name": {"@type":"xsd:string", "@value":"Darth Vader"},
"vehicle_name": {"@type":"xsd:string", "@value":"TIE Advanced x1"}},
{"person_name": {"@type":"xsd:string", "@value":"Boba Fett"},
"vehicle_name": {"@type":"xsd:string", "@value":"Slave 1"}}
]
We can ask for a specific example of a vehicle name by filtering on equality.
For instance:
let v = Vars("person","person_name","vehicle","vehicle_name");
select(v.person_name, v.vehicle_name)
.and(triple(v.vehicle, "pilot", v.person),
triple(v.vehicle, "label", v.vehicle_name),
triple(v.person, "label", v.person_name),
eq(v.vehicle_name, string("Millennium Falcon")))
Which results in:
[ {"person_name": {"@type":"xsd:string", "@value":"Chewbacca"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Han Solo"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Lando Calrissian"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}},
{"person_name": {"@type":"xsd:string", "@value":"Nien Nunb"},
"vehicle_name": {"@type":"xsd:string", "@value":"Millennium Falcon"}}
]
We can also write:
let v = Vars("person","person_name","vehicle","vehicle_name");
select(v.person_name, v.vehicle_name)
.and(triple(v.vehicle, "pilot", v.person),
triple(v.vehicle, "label", v.vehicle_name),
triple(v.person, "label", v.person_name),
not(eq(v.vehicle_name, string("Millennium Falcon"))))
In which we get the complement of the above.
Or, we can use the regex operator to get a wider variety, for instance:
let v = Vars("person","person_name","vehicle","vehicle_name","pattern");
select(v.person_name, v.vehicle_name)
.and(triple(v.vehicle, "pilot", v.person),
triple(v.vehicle, "label", v.vehicle_name),
triple(v.person, "label", v.person_name),
regex("W.*", v.vehicle_name, [v.pattern]))
In this case, we get:
[ {"person_name": {"@type":"xsd:string", "@value":"Darth Vader"},
"vehicle_name": {"@type":"xsd:string", "@value":"TIE Advanced x1"}},
{"person_name": {"@type":"xsd:string", "@value":"Arvel Crynyd"},
"vehicle_name": {"@type":"xsd:string", "@value":"A-wing"}},
{"person_name": {"@type":"xsd:string", "@value":"Chewbacca"},
"vehicle_name": {"@type":"xsd:string", "@value":"AT-ST"}}
]
Last modified 14d ago