Missing a test for table TRUNCATE while in transaction

Let's also test that truncate is still OK after closing the transaction, and add a test where the transaction is rolled back.

This should be better...

Oops

Marking the tests skipped if the db driver does not support transactions.

Thanks for review @borisson_!

Actually, all db_* functions are deprecated, so let's at least avoid introducing new usages. Also, as a db abstraction fan, I prefer to avoid usage of Connection::query on behalf of Connection::select as much as possible.

+++ b/core/tests/Drupal/KernelTests/Core/Database/DeleteTruncateTest.php
@@ -2,6 +2,8 @@
+use Drupal\Core\Database\Database;
+
 /**
  * Tests delete and truncate queries.
  *
@@ -17,6 +19,21 @@

@@ -17,6 +19,21 @@
  */
 class DeleteTruncateTest extends DatabaseTestBase {
 
+  /**
+   * The database connection for testing.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->connection = Database::getConnection();
+  }
+
   /**

It might be worthwhile to move this hunk to the DatabaseTestBase parent class, so that all the test subclasses could replace calls to db_* function with $this->connection->*() calls instead of the \Drupal::database()->* calls that I see are being suggested in the issues that are removing usage of deprecated db_* functions. Some core committer feedback would help, this could also be a followup if deemed relevant.

Thanks @alexpott, any comment re. #15?

Opened #2953385: Add a $connection property to DatabaseTestBase kernel test class to be used by extending classes