Bug(SQLite3): Forge::dropColumn() seems to always return false

[mkuettel]

PHP Version

8.3

CodeIgniter4 Version

4.5.1

CodeIgniter4 Installation Method

Composer (as dependency to an existing project)

Which operating systems have you tested for this bug?

Linux

Which server did you use?

cli

Database

SQLite3

What happened?

I was checking whether dropColumn of forge returned false when migrating down. Which always seemed to be the case.
When checking the implementation I noticed that Forge expects from the driver that _alterTable returns a SQL statement to be executed, but in this case SQLite3 will return an empty string, because it runs multiple statements in the background, creating a new temporary table without the specified columns, moving data over and renaming afterwards.

Steps to Reproduce

<?php

declare(strict_types=1);

namespace App\Database\Migrations;

use CodeIgniter\Database\Exceptions\DatabaseException;
use CodeIgniter\Database\Migration;

class AddAColumnToExistingTable extends Migration
{
 protected string $table = 'existing_table';

 public function up(): void
 {
 $this->forge->addColumn($this->table, [
 'column' => ['type' => 'varchar', 'null' => false],
 ]) or throw new DatabaseException("Could not add columns to table {$this->table}: " . var_export($this->db->error(), true));
 }

 public function down(): void
 {
 $this->forge->dropColumn($this->table, 'column')
 or throw new DatabaseException("Could drop column from table {$this->table}: " . var_export($this->db->error(), true));
 }
}

Expected Output

None, but the DatabaseException is thrown in the down() method, telling me that no error occured.
But dropColumn() returned false, because the statement is empty.

Anything else?

No response

[kenjis]

I confirmed the bug.

--- a/tests/system/Database/Live/ForgeTest.php
+++ b/tests/system/Database/Live/ForgeTest.php
@@ -1317,7 +1317,9 @@ final class ForgeTest extends CIUnitTestCase
 
 $this->assertTrue($this->db->fieldExists('name', 'forge_test_two'));
 
- $this->forge->dropColumn('forge_test_two', 'name');
+ $return = $this->forge->dropColumn('forge_test_two', 'name');
+
+ $this->assertTrue($return);
 
 $this->db->resetDataCache();
 

1) CodeIgniter\Database\Live\ForgeTest::testDropColumn
Failed asserting that false is true.