QueryKit

QueryKit, a simple CoreData query language.

Usage

Person.queryset(context).filter(Person.name == "Kyle").delete()

Querying

To retrieve objects from CoreData with QueryKit, you can construct a QuerySet for your model in a managed object context.

A queryset is an immutable object, any operation will return a new queryset instead of modifying the queryset.

var queryset = Person.queryset(context)

Filtering

You can filter a queryset using the filter and exclude methods, which accept a predicate and return a new queryset.

queryset.filter(NSPredicate(format:"name == %@", "Kyle"))
queryset.filter(Person.name == "Kyle")
queryset.exclude(Person.age < 21)
queryset.exclude(Person.isEmployed)

Ordering

You can order a queryset's results by using the orderBy method which accepts a collection of sort descriptors:

queryset.orderBy(NSSortDescriptor(key: "name", ascending: true))
queryset.orderBy(Person.name.ascending)
queryset.orderBy([Person.name.ascending, Person.age.descending])

Slicing

You can use slicing to limit a queryset to a range. For example, to get the first 5 items:

queryset[0..5]

Fetching

Single object

var kyle = queryset.filter(Person.name == "Kyle").get()

Object at index

var orta = queryset[3]

Count

queryset.count()

Iteration

for person in queryset {
    println(person.name)
}

Conversion to an array

queryset.array()

Deleting

This method immediately deletes the objects in your queryset and returns a count and an error if the operation failed.

queryset.delete()

Attributes

The Attribute is a generic structure for creating predicates providing type-safety.

let name = Attribute<String>("name")
let age = Attribute<Int>("age")

name == "Kyle"
name << ["Kyle", "Katie"]

age == 27
age >= 25
age << (22...30)

Operators

Comparison	Meaning
==	x equals y
!=	x is not equal to y
<	x is less than y
<=	x is less than or equal to y
>	x is more than y
>=	x is more than or equal to y
~=	x is like y
~=	x is like y
<<	x IN y, where y is an array
<<	x BETWEEN y, where y is a range

Predicate extensions

We've extended NSPredicate to add support for the !, && and || operators for joining predicates together.

NSPredicate(format:"name == Kyle") || NSPredicate(format:"name == Katie")
NSPredicate(format:"age >= 21") && !NSPredicate(format:"name == Kyle")

Person.name == "Kyle" || Person.name == "Katie"
Person.age >= 21 || Person.name != "Kyle"

License

QueryKit is released under the BSD license. See LICENSE.

anthony0982/QueryKit