Why is COUNT(CASE WHEN...) seemingly stopping full MYSQL query retrieval? - php

Question

I have a table called "guesses" that stores peoples guesses whether a baby is a boy or a girl. Those are the two possible things in the "sex" column (i.e. "boy" or "girl).
There are 4 guesses in the table for this poolid. So if I run this code below...
$sql = "SELECT
FROM guesses
WHERE poolid = '$poolid'
ORDER BY $sort, createddate";
$getguesses = mysqli_query($connection, $sql);
if (!$getguesses) {
die("Database query failed: " . mysqli_error($connection));
} else {
//Get total number of guesses
$numguesses=mysqli_num_rows($getguesses);
echo "NUMGUESSES: $numguesses";
while ($row = mysqli_fetch_array($getguesses)) {
//code to grab other info about guesses, not relevant, works fine
}
}
It outputs
NUMGUESSES: 4
And also spits out 4 lines (one for each guess) with other info that isn't relevant.
I would like to count the total number of girl guesses vs. boy guesses, for use later in a pie chart. So I did the following...
$sql = "SELECT *, COUNT(CASE WHEN `sex` = 'girl' then 1 ELSE NULL END) as 'totalgirls', COUNT(CASE WHEN `sex` = 'boy' then 1 ELSE NULL END) as 'totalboys'
FROM guesses
WHERE poolid = '$poolid'
ORDER BY $sort, createddate";
$getguesses = mysqli_query($connection, $sql);
if (!$getguesses) {
die("Database query failed: " . mysqli_error($connection));
} else {
//Get total number of guesses
$numguesses=mysqli_num_rows($getguesses);
echo "NUMGUESSES: $numguesses";
while ($row = mysqli_fetch_array($getguesses)) {
echo "GIRLS:". $row['totalgirls'];
echo "BOYS:". $row['totalboys'];
//code to grab other info about guesses, not relevant
}
}
This outputs
NUMGUESSES: 1
GIRLS: 4
BOYS: 0
And also spits out ONLY ONE line (for only one of the four existing guesses)
All four guesses are girls, so the GIRLS total and the BOYS total are correct. But why is it only seeing NUMGUESSES as 1 now? It should be 4 and should show 4 lines of guesses.
Something with the COUNT() is throwing something off. Any ideas?

Answer 1

You're asking mysql to count, so it outputs one line ; )
Try this instead:
$sql = "SELECT COUNT(*), SUM(CASE WHEN `sex` = 'girl' then 1 ELSE 0 END) as.....
Beware of including NULL values in a count!