Query API

Queries are an object created from the Model API. Once created, you can add a number of steps to the query to get your desired results from the database. Queries are only executed after calling Query.evaluate(), which will return a promise with the appropriate results.

Query.all()

Add a step to the query that collects all records.

Query.get(lookupArgs)

Add a step to the query that collects a single record based on the lookup arguments.

Arguments:
  • lookupArgs (object) – An object literal with lookup arguments.
Query.filter(lookupArgs)

Add a step to the query that filters records based on the lookup arguments.

Arguments:
  • lookupArgs (object) – An object literal with lookup arguments.
Query.exclude(lookupArgs)

Add a step to the query that excludes records based on the lookup arguments.

Arguments:
  • lookupArgs (object) – An object literal with lookup arguments.
Query.evaluate([options])

Evaluate the query as built and return the record[s] collected in a promise.

Arguments:
  • options (object) –

    Options are provided as an object, but are not required. For now there is only one option available:

    depth: Decide how deeply the evaluation will go to collect relations. By default this argument is set at 1 and will collect the nearest relations only. Raising the depth can greatly increase the execution time and result in circular record collection, which is not optimised at present.
Return Promise<records>:
 

Promise resolves once the records and all depth recovered records are collected.

Lookup Arguments

Most query steps will require lookup arguments to be used. The lookup arguments are an object literal with keys that define which field to target, and values which define what to match against. By default lookup arguments query for an exact match, but you can also provide modifiers as a postfix to the fields, for example age__gt for the everything greater than on the field age.

Modifiers

__gt:Greater than the query value.
__gte:Greater than or equal to the query value.
__lt:Less than the query value.
__lte:Less than or equal to the query value.
__in:Equals one of the query value, which must be an array.

Relational Queries

It is possible to perform lookups based on the fields of related objects. For example, if you had a person record with a relation home, you could query against it like so:

// filter all people who live in a home in the suburb 'Moonah'
db.models.Person.query().filter({'home__suburb': 'Moonah'}).evaluate();

Field names must be separated with two underscores. You can add modifiers to the end.