system/Database/SQLite3/Forge.php
protected function _processColumn(array $field): string
	{
		if ($field['type'] === 'TEXT' && strpos($field['length'], "('") === 0)
		{
			$field['type'] .= ' CHECK(' . $this->db->escapeIdentifiers($field['name'])
				. ' IN ' . $field['length'] . ')';
		}

		return $this->db->escapeIdentifiers($field['name'])
			   . ' ' . $field['type']
			   . $field['auto_increment']
			   . $field['null']
			   . $field['unique']
			   . $field['default'];
	}
protected function _processColumn(array $field): string
	{
		if ($field['type'] === 'TEXT' && strpos($field['length'], "('") === 0)
		{
			$field['type'] .= ' CHECK(' . $this->db->escapeIdentifiers($field['name'])
				. ' IN ' . $field['length'] . ')';
		}

		return $this->db->escapeIdentifiers($field['name'])
			   . ' ' . $field['type']
			   . $field['auto_increment']
			   . $field['null']
			   . $field['unique']
			   . $field['default'];
	}
Process column

@param array $field

@return string