--- /dev/null
+<?php
+
+namespace Drupal\system\Tests\Database;
+
+/**
+ * Tests the temporary query functionality.
+ *
+ * @group Database
+ */
+class TemporaryQueryTest extends DatabaseWebTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['database_test'];
+
+ /**
+ * Returns the number of rows of a table.
+ */
+ public function countTableRows($table_name) {
+ return db_select($table_name)->countQuery()->execute()->fetchField();
+ }
+
+ /**
+ * Confirms that temporary tables work and are limited to one request.
+ */
+ public function testTemporaryQuery() {
+ $this->drupalGet('database_test/db_query_temporary');
+ $data = json_decode($this->getRawContent());
+ if ($data) {
+ $this->assertEqual($this->countTableRows('test'), $data->row_count, 'The temporary table contains the correct amount of rows.');
+ $this->assertFalse(db_table_exists($data->table_name), 'The temporary table is, indeed, temporary.');
+ }
+ else {
+ $this->fail('The creation of the temporary table failed.');
+ }
+
+ // Now try to run two db_query_temporary() in the same request.
+ $table_name_test = db_query_temporary('SELECT name FROM {test}', []);
+ $table_name_task = db_query_temporary('SELECT pid FROM {test_task}', []);
+
+ $this->assertEqual($this->countTableRows($table_name_test), $this->countTableRows('test'), 'A temporary table was created successfully in this request.');
+ $this->assertEqual($this->countTableRows($table_name_task), $this->countTableRows('test_task'), 'A second temporary table was created successfully in this request.');
+
+ // Check that leading whitespace and comments do not cause problems
+ // in the modified query.
+ $sql = "
+ -- Let's select some rows into a temporary table
+ SELECT name FROM {test}
+ ";
+ $table_name_test = db_query_temporary($sql, []);
+ $this->assertEqual($this->countTableRows($table_name_test), $this->countTableRows('test'), 'Leading white space and comments do not interfere with temporary table creation.');
+ }
+
+}