Using DISTINCT in a CakePHP find function

Question

I am writing a CakePHP 1.2 app. I have a list of people that I want the user to be able to filter on different fields. For each filterable field, I have a drop down list.

Answer 1

Just group by the fields that you want to get distinct.. or use Set::extract() and then array_unique()

Answer 2

Here's how I did it in CakePHP 3.x:

     $query = $this->MyTables->find('all');
     $result = $query->distinct()->toArray();

Answer 3

Yes I also tried to fetch unique results with 'list' but its not working. Then I fixed the problem by using 'all'.

Answer 4

Using SQL grouping will also produce a distinct list. Not sure of the negative consequences if any, but it seems to work fine for me.

$first_names = $this->Person->find('list', array(
    'fields' => 'first_name',
    'order' => 'first_name',
    'group' => 'first_name',
    'conditions' => array('Person.status' => '1'),
));
$this->set('first_names', $first_names);

Answer 5

I know it is a question for CakePHP 1.2, but I was searching for that too with CakePHP version 3. And in this version there is a method to form the Query into a distinct one:

$first_names = $this->Persons->find(
    'list',
    [
        'fields'=> ['name']
    ]
)
  ->distinct();
;

This will generate a sql query like this:

SELECT DISTINCT Persons.name AS `Persons__name` FROM persons Persons

But the distinct method is a bit mightier than just inserting DISTINCT in the query.

If you want to just distinct the result on one field, so just throwing away a row with a duplicated name, you can also use the distinct method with an array of the fields as parameter:

$first_names = $this->Persons->find(
    'list',
    [
        'fields'=> ['id', 'name'] //it also works if the field isn't in the selection
    ]
)
  ->distinct(['name']); //when you use more tables in the query, use: 'Persons.name'
;

This will general a sql query like this (for sure it is a group query):

SELECT DISTINCT
    Persons.id AS `Persons__id`, Persons.name AS `Persons__name`
FROM persons Persons
GROUP BY name #respectively Persons.name

Hope I will help some for CakePHP 3. :)

Answer 6

Try to use 'group by', it works perfectry:

$first_names = $this->Person->find('list', array(
  'fields'=>'first_name',
   'order'=>'Person.first_name ASC',
   'conditions'=> array('Person.status'=>'1'),
   'group' => 'first_name'));