Yii2 : How to write distinct SQL query? - php

Question

I want to implement following SQL queries in Yii 2 but with no success.
This should give total number of unique company names:
SELECT count(DISTINCT(company_name)) FROM clients
And this should display company_name with client code and id(PK):
SELECT (DISTINCT(company_name,client_code)) FROM clients
How to achieve this?

Answer 1

Try this:
$total = YourModel::find()->select('company_name')->distinct()->count();
In Search Model:
public function search($params)
{
$query = YourModel::find()->select('company_name')->distinct();
// or
$query = YourModel::find()->select(['company_name', 'client_code'])->distinct();
$query->orderBy('id desc');
$dataProvider = new ActiveDataProvider([
'query' => $query,
]);
// ...
}

Answer 2

Answering my own question I got following working solutions:
Got the count for unique company_name:
$my = (new yii\db\Query())
->select(['company_name',])
->from('create_client')
->distinct()
->count();
echo $my;
List of distinct company_name and client_code:
$query = new yii\db\Query();
$data = $query->select(['company_name','client_code'])
->from('create_client')
->distinct()
->all();
if ($data) {
foreach ($data as $row) {
echo 'company_name: ' . $row['company_name'] . ' client_code: ' . $row['client_code'] . '<br>';
}
}

Answer 3

All worked fine
return Clients::find()->count('DISTINCT(company_name)');

Answer 4

I hope this sample is useful for you
$names = Yii::$app->db->createCommand('SELECT count(DISTINCT(company_name)) as name FROM clients')
->queryAll();
for access the the data
foreach ($names as $name){
echo $name['name'];
}

Answer 5

For those who need select distinct on and other columns with aliases, the following solution will work:
$modelClass::find()
->select(new Expression(
"distinct on ('col1') col1, col2, test as col3, 'hardCodeValue' as col4"
))
Note: for PGSQL it is important what quotes you put in the query.