PHP MySQL Queries - Addition - php

Question

I am working on a formula where I am adding multiple values in a row and column depending on the values of other cells. For example I have the following working code:
$result = mysql_query("SELECT School,SUM(Wins + Losses) as total FROM tennis GROUP BY School");
echo "<table border='1'>
<tr>
<th>School</th>
<th>Score</th>
</tr>";
while($row = mysql_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $row['School'] . "</td>";
echo "<td>" . $row['total'] . "</td>";
echo "</tr>";
}
However I want to add more columns that are also sums of other rows/columns and don't know how to do this while still keeping everything Grouped by the column 'School'. What I essentially want is the following, but the code is incorrect:
$result = mysql_query("SELECT School,SUM(Wins + Losses) as 1sttotal FROM tennis WHERE Event='1st Singles', SUM(Wins + Losses) as 2ndtotal FROM tennis WHERE Event='2nd Singles' GROUP BY School");
echo "<table border='1'>
<tr>
<th>School</th>
<th>1st Singles</th>
<th>2nd Singles</th>
</tr>";
while($row = mysql_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $row['School'] . "</td>";
echo "<td>" . $row['1sttotal'] . "</td>";
echo "<td>" . $row['2ndtotal'] . "</td>";
echo "</tr>";
}
I'm new to PHP so I'm not sure the correct/optimal way to go about setting this up. Thanks

Answer 1

this is the query you should use to get the 2 totals:
SELECT
School,
SUM(IF(Event='1st Singles', Wins + Losses, 0)) as 1sttotal,
SUM(IF(Event='2nd Singles', Wins + Losses, 0)) as 2ndtotal
FROM tennis
GROUP BY School;
See how it adds according to the event columns? The trick is to pass a WHERE filter within the SELECT clause through conditional execution (IF)
Other possibility using CASE WHEN:
SELECT
School,
SUM(
CASE
WHEN Event='1st Singles' THEN Wins + Losses
ELSE 0
END
) as 1sttotal,
SUM(
CASE
WHEN Event='2nd Singles' THEN Wins + Losses
ELSE 0
END
) as 2ndtotal
FROM tennis
GROUP BY School;