2.2 KiB
DataObjectSet
Introduction
This class represents a set of [api:DataObject]'s, such as the results of a query. It is the base for all datamodel-related querying. It implements the Iterator interface introduced in PHP5.
Relations (has_many/many_many) are described in [api:ComponentSet], a subclass of [api:DataObjectSet].
Usage
Getting the size
:::php
$mySet->Count();
Getting an single element
:::php
$myFirstDataObject = $mySet->First();
$myLastDataObject = $mySet->Last();
Getting multiple elements
:::php
$mySpecialDataObjects = $mySet->find('Status', 'special');
$startingFromTen = $mySet->getOffset(10);
$tenToTwenty = $mySet->getRange(10, 10);
Getting one property
:::php
$myIDArray = $mySet->column('ID');
Grouping
You can group a set by a specific column. Consider using [api:SQLQuery] with a GROUP BY statement for enhanced performance.
:::php
$groupedSet = $mySet->groupBy('Lastname');
Sorting
Sort a set by a specific column.
:::php
$mySet->sort('Lastname'); //ascending
$mySet->sort('Lastname', 'DESC'); //descending
This works on the object itself, so do NOT do something like this:
:::php
$sortedSet = $mySet->sort('Lastname'); //ascending
Merge with other [api:DataObjectSet]s
:::php
$myFirstSet->merge($mySecondSet);
// $myFirstSet now contains all combined values
Mapping for Dropdowns
When using [api:DropdownField] and its numerous subclasses to select a value from a set, you can easily map the records to a compatible array:
:::php
$map = $mySet->toDropDownMap('ID', 'Title');
$dropdownField = new DropdownField('myField', 'my label', $map);
Converting to array
:::php
$myArray = $mySet->toArray();
Checking for existence
It is good practice to check for empty sets before doing any iteration.
:::php
$mySet = DataObject::get('Players');
if($mySet->exists()) foreach($mySet as $player)
Paging
[api:DataObject]s have native support for dealing with pagination. See setPageLimits, setPageLength, etc.
FIXME Complete pagination documentation
API Documentation
[api:DataObjectSet]