如何获得两列之间的总价？

Question

实施例：     $ from = 30和$ to = 33。 现在我希望得到$ from和$ to之间的总价。

这是我的代码。

$from = $_POST['from'];
$to = $_POST['to'];
$result = mysql_query("SELECT SUM(price) as totalPrice FROM price WHERE price BETWEEN '$from' and '$to'"); 
$row = mysql_fetch_assoc($result); 
$sum = $row['totalPrice'];

Answer 1

- (NSString *)displayName
{   
    NSMutableString *displayName = [NSMutableString stringWithString:[super displayName]];

    if ([self fileURL] == nil) {
        NSString *firstCharacter = [[displayName substringToIndex:1] lowercaseString];
        [displayName deleteCharactersInRange:NSMakeRange(0, 1)];
        [displayName insertString:firstCharacter atIndex:0];
    }

    return [NSString stringWithString:displayName];
}

Answer 2

SELECT sum(`price`) as total FROM `table` where from = 30 AND `to` = 33

..可能会改变，或者依赖于你想要的东西。