Modified sqlValue member to address 'character varying', 'timestamp' cases. Fixes docblock and added some break. What's your thought about?

postgresqlValue.php

	/**
	 * This function return a field value as a prepared string to be used in a SQL statement.
	 *
	 * @param   array   $columns      Array of table's column returned by ::getTableColumns.
	 * @param   string  $field_name   The table field's name.
	 * @param   string  $field_value  The variable value to quote and return.
	 * 
	 * @return  string  The quoted string.
	 *
	 * @since   11.3
	 */
	public function sqlValue($columns, $field_name, $field_value)
	{
		switch ($columns[$field_name])
		{
			case 'boolean':
				if ($field_value == 't')
				{
					$field_value = true;
				}
				$val = is_bool($field_value) ? ( $field_value ? 'TRUE' : 'FALSE' ) : 'NULL';
				break;
			case 'bigint':
			case 'bigserial':
			case 'integer':
			case 'money':
			case 'numeric':
			case 'real':
			case 'smallint':
			case 'serial':
			case 'character varying':
				$val = strlen($field_value) == 0 ? 'NULL' : $field_value;
				break;
			case 'date':
			case 'timestamp without time zone':
				if (empty($field_value))
				{
					$field_value = $this->getNullDate();
				}
				break;
			default:
				$val = $this->quote($field_value);
		}

		return $val;
	}