Fix drop column with array

system/Database/Forge.php

@@ -816,13 +816,13 @@ public function addColumn(string $table, $field): bool
 	/**
 	 * Column Drop
 	 *
-	 * @param string $table       Table name
-	 * @param string $column_name Column name
+	 * @param string       $table       Table name
+	 * @param string|array $column_name Column name Array or comma separated
 	 *
 	 * @return mixed
 	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
 	 */
-	public function dropColumn(string $table, string $column_name)
+	public function dropColumn(string $table, $column_name)
 	{
 		$sql = $this->_alterTable('DROP', $this->db->DBPrefix . $table, $column_name);
 		if ($sql === false)
@@ -897,24 +897,33 @@ public function modifyColumn(string $table, $field): bool
 	 *
 	 * @param string $alter_type ALTER type
 	 * @param string $table      Table name
-	 * @param mixed  $field      Column definition
+	 * @param mixed  $fields     Column definition
 	 *
 	 * @return string|string[]
 	 */
-	protected function _alterTable(string $alter_type, string $table, $field)
+	protected function _alterTable(string $alter_type, string $table, $fields)
 	{
 		$sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table) . ' ';
 
 		// DROP has everything it needs now.
 		if ($alter_type === 'DROP')
 		{
-			return $sql . 'DROP COLUMN ' . $this->db->escapeIdentifiers($field);
+			if (is_string($fields))
+			{
+				$fields = explode(',', $fields);
+			}
+
+			$fields = array_map(function ($field) {
+				return 'DROP COLUMN ' . $this->db->escapeIdentifiers(trim($field));
+			}, $fields);
+
+			return $sql . implode(', ', $fields);
 		}
 
 		$sql .= ($alter_type === 'ADD') ? 'ADD ' : $alter_type . ' COLUMN ';
 
 		$sqls = [];
-		foreach ($field as $data)
+		foreach ($fields as $data)
 		{
 			$sqls[] = $sql
 					  . ($data['_literal'] !== false ? $data['_literal'] : $this->_processColumn($data));

system/Database/SQLite3/Table.php

@@ -185,15 +185,29 @@ public function run(): bool
 	}
 
 	/**
-	 * Drops a column from the table.
+	 * Drops columns from the table.
 	 *
-	 * @param string $column
+	 * @param string|array $columns
 	 *
 	 * @return \CodeIgniter\Database\SQLite3\Table
 	 */
-	public function dropColumn(string $column)
+	public function dropColumn($columns)
 	{
-		unset($this->fields[$column]);
+		//unset($this->fields[$column]);
+
+		if (is_string($columns))
+		{
+			$columns = explode(',', $columns);
+		}
+
+		foreach ($columns as $column)
+		{
+			$column = trim($column);
+			if (isset($this->fields[$column]))
+			{
+				unset($this->fields[$column]);
+			}
+		}
 
 		return $this;
 	}

tests/system/Database/Live/ForgeTest.php

@@ -759,4 +759,80 @@ public function testDropTableSuccess()
 			$this->assertCount(0, $this->db->getIndexData('droptest'));
 		}
 	}
+
+	public function testDropMultipleColumnWithArray()
+	{
+		$this->forge->dropTable('forge_test_two', true);
+
+		$this->forge->addField([
+			'id'    => [
+				'type'           => 'INTEGER',
+				'constraint'     => 11,
+				'unsigned'       => false,
+				'auto_increment' => true,
+			],
+			'name'  => [
+				'type'       => 'varchar',
+				'constraint' => 255,
+				'null'       => true,
+			],
+			'email' => [
+				'type'       => 'varchar',
+				'constraint' => 255,
+				'null'       => true,
+			],
+		]);
+
+		$this->forge->addKey('id', true);
+		$this->forge->createTable('forge_test_two');
+
+		$this->assertTrue($this->db->fieldExists('name', 'forge_test_two'));
+
+		$this->forge->dropColumn('forge_test_two', ['id', 'name']);
+
+		$this->db->resetDataCache();
+
+		$this->assertFalse($this->db->fieldExists('id', 'forge_test_two'));
+		$this->assertFalse($this->db->fieldExists('name', 'forge_test_two'));
+
+		$this->forge->dropTable('forge_test_two', true);
+	}
+
+	public function testDropMultipleColumnWithString()
+	{
+		$this->forge->dropTable('forge_test_four', true);
+
+		$this->forge->addField([
+			'id'    => [
+				'type'           => 'INTEGER',
+				'constraint'     => 11,
+				'unsigned'       => false,
+				'auto_increment' => true,
+			],
+			'name'  => [
+				'type'       => 'varchar',
+				'constraint' => 255,
+				'null'       => true,
+			],
+			'email' => [
+				'type'       => 'varchar',
+				'constraint' => 255,
+				'null'       => true,
+			],
+		]);
+
+		$this->forge->addKey('id', true);
+		$this->forge->createTable('forge_test_four');
+
+		$this->assertTrue($this->db->fieldExists('name', 'forge_test_four'));
+
+		$this->forge->dropColumn('forge_test_four', 'id, name');
+
+		$this->db->resetDataCache();
+
+		$this->assertFalse($this->db->fieldExists('id', 'forge_test_four'));
+		$this->assertFalse($this->db->fieldExists('name', 'forge_test_four'));
+
+		$this->forge->dropTable('forge_test_four', true);
+	}
 }

user_guide_src/source/dbmgmt/forge.rst

@@ -313,7 +313,7 @@ Examples::
 		'preferences' => ['type' => 'TEXT', 'first' => TRUE]
 	];
 
-Dropping a Column From a Table
+Dropping Columns From a Table
 ==============================
 
 **$forge->dropColumn()**
@@ -322,7 +322,14 @@ Used to remove a column from a table.
 
 ::
 
-	$forge->dropColumn('table_name', 'column_to_drop');
+	$forge->dropColumn('table_name', 'column_to_drop'); // to drop one single column
+
+Used to remove multiple columns from a table.
+
+::
+
+    $forge->dropColumn('table_name', 'column_1,column_2'); // by proving comma separated column names
+    $forge->dropColumn('table_name', ['column_1', 'column_2']); // by proving array of column names
 
 Modifying a Column in a Table
 =============================
@@ -415,11 +422,11 @@ Class Reference
 	.. php:method:: dropColumn($table, $column_name)
 
 		:param	string	$table: Table name
-		:param	array	$column_name: The column name to drop
+		:param	mixed	$column_names: Comma-delimited string or an array of column names
 		:returns:	TRUE on success, FALSE on failure
 		:rtype:	bool
 
-		Drops a column from a table. Usage:  See `Dropping a Column From a Table`_.
+		Drops single or multiple columns from a table. Usage:  See `Dropping Columns From a Table`_.
 
 	.. php:method:: dropDatabase($dbName)