Sum a field in mysql [duplicate] - php

Question

This question already has answers here:
Get sum of MySQL column in PHP
(9 answers)
Closed 9 years ago.
how do I get the output from this:
$VisitorsProfile = $mysql->query("SELECT SUM(views) FROM visitors_profile WHERE publisher = '123456'");
I tryed this but nothing prints me out!
<?php echo $VisitorsProfile['sum'] ?>
Any suggestions?

Answer 1

you need to name the column, I know it sounds weird but it should be
$VisitorsProfile = $mysql->query("SELECT SUM(views) as totals FROM visitors_profile WHERE publisher = '123456'");
and as indicated as below you need the mysql_fetch_assoc function on the query so you can reference it by name.
Then you can reference it by
<?php echo $VisitorsProfile['totals'] ?>
you just need to reference it "as" something. whatever you put in after the word as is what you can refer to it by, i wouldn't use something like "sum" as that is a mysql function and can cause problems.

Answer 2

PHP allows you to get the information by column name or by column index. The recommended way is to do it by column name, because this will allow you to change your query's column order without affecting your PHP code.
So to get it you need to add a column alias to your query:
$rs = mysql_query("SELECT SUM(value) AS total FROM visitors_profile WHERE publisher = '123456'");
if ($row = mysql_fetch_assoc($rs)) {
echo $row['total'];
}
On the first line you are actually running the query. Check the column alias: "total".
On the second line you are asking for an array or specifically a "map" from the result set. In other words, by calling mysql_fetch_assoc you are asking for an array whose elements are available by name. That array represents a row from your result set.
On the third line you are printing the actual sum.
Check the "if" in the $row assignment. This will help you validate there is a result row before trying to print it. I recommend you to do the same on the line where you call mysql_query.
EDIT:
Sorry, I think you are using objects, so it should look like this:
$rs = $mysql->query("SELECT SUM(value) AS total FROM visitors_profile WHERE publisher = '123456'");
if ($row = $mysql->fetch_assoc($rs)) {
echo $row['total'];
}