public function SelectSubqueryTest::testFromSubquerySelect in Drupal 9

Same name and namespace in other branches

1. 8 core/tests/Drupal/KernelTests/Core/Database/SelectSubqueryTest.php \Drupal\KernelTests\Core\Database\SelectSubqueryTest::testFromSubquerySelect()

Tests that we can use a subquery in a FROM clause.

File

core/tests/Drupal/KernelTests/Core/Database/SelectSubqueryTest.php, line 15

Class

SelectSubqueryTest

Tests the Select query builder.

Namespace

Drupal\KernelTests\Core\Database

Code

public function testFromSubquerySelect() {

  // Create a subquery, which is just a normal query object.
  $subquery = $this->connection
    ->select('test_task', 'tt');
  $subquery
    ->addField('tt', 'pid', 'pid');
  $subquery
    ->addField('tt', 'task', 'task');
  $subquery
    ->condition('priority', 1);
  for ($i = 0; $i < 2; $i++) {

    // Create another query that joins against the virtual table resulting
    // from the subquery.
    $select = $this->connection
      ->select($subquery, 'tt2');
    $select
      ->join('test', 't', '[t].[id] = [tt2].[pid]');
    $select
      ->addField('t', 'name');
    if ($i) {

      // Use a different number of conditions here to confuse the subquery
      // placeholder counter, testing https://www.drupal.org/node/1112854.
      $select
        ->condition('name', 'John');
    }
    $select
      ->condition('task', 'code');

    // The resulting query should be equivalent to:
    // @code
    // SELECT t.name
    // FROM (SELECT tt.pid AS pid, tt.task AS task FROM test_task tt WHERE priority=1) tt
    //   INNER JOIN test t ON t.id=tt.pid
    // WHERE tt.task = 'code'
    // @endcode
    $people = $select
      ->execute()
      ->fetchCol();
    $this
      ->assertCount(1, $people, 'Returned the correct number of rows.');
  }
}