在PHP中回应表的总和

I have 2 columns in a table called Points. The 2 columns are UserPoints and UserID.

我在一个名为Points的表中有2列。 2列是UserPoints和UserID。

I want to be able to echo the total amount of points a user has.

我希望能够回显用户拥有的总积分数。

I've got something like this but I dont think its right.

我有类似的东西，但我认为没错。

$getTotalPoints = mysql_query("SELECT SUM(UserPoints) FROM `Points` WHERE `UserID` = '1'") or die(mysql_error()); 
$totalPoints = mysql_fetch_array($getTotalPoints);

When i echo the above statement by echoing "$totalPoints" i get "Array".

当我通过回显“$ totalPoints”来回应上述陈述时，我得到“数组”。

Anyone know the correct query to do this ?

有人知道正确的查询吗？

4 个解决方案

#1

You're getting Array because that's what's stored in $totalPoints. Look closely at your code and you'll see you used the mysql_fetch_array() function, which retrieves a row of results from the results set as an array. If you do var_dump() on $totalPoints you'll see the following:

你得到的数组是因为这是存储在$ totalPoints中的数据。仔细查看您的代码，您将看到使用了mysql_fetch_array（）函数，该函数从结果集中检索一行结果作为数组。如果你在$ totalPoints上做var_dump（），你会看到以下内容：

Array
(
    [0] => 12345
    [SUM(UserPoints)] => 12345
)

The sum you're looking for is at index 0 or the column name, in this case SUM(UserPoints), so you can output it using echo $totalPoints[0] or echo $totalPoints['SUM(UserPoints)'].

您要查找的总和是索引0或列名称，在本例中为SUM（UserPoints），因此您可以使用echo $ totalPoints [0]或echo $ totalPoints ['SUM（UserPoints）']输出它。

Alternatively, you could use the mysql_result() function. I think this is more in-line with the behavior you were expecting. It fetches a single value from the row from the result set. So, instead of mysql_fetch_array() you'd wrote:

或者，您可以使用mysql_result（）函数。我认为这更符合你期望的行为。它从结果集中的行中获取单个值。所以，你写的不是mysql_fetch_array（），而是写了：

$totalPoints = mysql_result($result, 0);

For more information on mysql_result(), check out the PHP documentation for it.

有关mysql_result（）的更多信息，请查看它的PHP文档。

As an aside, I would recommend not using mysql_* functions if you have the option. A newer interface like PDO, or at least mysqli, would be better. This will depend on your project of course... if you're working with a large legacy code base it may be difficult to change. But if you're starting out now, I think you'd benefit from the newer libraries. You can see my opinion and some guidance on transitioning extensions in this article I wrote.

顺便说一句，如果您有选项，我建议不要使用mysql_ *函数。像PDO这样的新界面，或者至少是mysqli，会更好。这当然取决于您的项目......如果您正在使用大型遗留代码库，则可能很难更改。但如果你现在开始，我想你会从新的图书馆中受益。您可以在我写的这篇文章中看到我对转换扩展的看法和一些指导。

Hope this helped... and good luck!

希望这有帮助......祝你好运！

#2

mysql_fetch_array fetches a result row as an associative array, a numeric array, or both. by default it creates both. all that you need is to echo $totalPoints[0];

mysql_fetch_array将结果行提取为关联数组，数字数组或两者。默认情况下它会同时创建。所有你需要的是回显$ totalPoints [0];

or, if you rewrite you request as

或者，如果你重写你的请求

$getTotalPoints = mysql_query("SELECT SUM(UserPoints) total FROM `Points` 
        WHERE `UserID` = '1'") or die(mysql_error()); 
$totalPoints = mysql_fetch_array($getTotalPoints);
echo $totalPoints['total'];

#3

mysql_fetch_array returns an array. Therefore you need to treat $totalpoints as an array.

mysql_fetch_array返回一个数组。因此，您需要将$ totalpoints视为数组。

try adding this line to the end of your snippet:

尝试将此行添加到代码段的末尾：

echo $totalPoints[0];

echo $ totalPoints [0];

There are several ways to retrieve data with the mysql functions I suggest reading about them in the php manual.

有几种方法可以使用mysql函数检索数据，我建议在php手册中阅读它们。

Here is mysql_fetch_array

这是mysql_fetch_array

#4

The resultset row is an array with as many elements as you got in the SELECT. In you case you only got 1 element (the sum). So you should: echo $totalPoints[0]; If you need to debug this kind of issues I recommend you to read about print_r function.

结果集行是一个数组，其中包含与SELECT中相同的元素。在你的情况下，你只有1个元素（总和）。所以你应该：echo $ totalPoints [0];如果您需要调试此类问题，我建议您阅读有关print_r函数的信息。

#1

Array
(
    [0] => 12345
    [SUM(UserPoints)] => 12345
)