PHP - replace subquery with join? - php

Question

Ok, so right now i have a query inside of the while loop from another query...but there's got to be a more efficient way of doing what i'm trying to do. Can i accomplish the below script via one query? And would that be more efficient? (i'm assuming it would be) Here's what i have now (not the real code, but a good example):
$sth = $dbh->prepare("SELECT * FROM Bugs LIMIT 5");
$sth->setFetchMode(PDO::FETCH_OBJ);
$sth->execute();
while($row = $sth->fetch()){
$bugId = $row->id;
echo 'Bug Name: ' . $row->name;
echo '<br />';
echo 'Affected Web Browsers: ';
$sth2 = $dbh->prepare("SELECT * FROM AffectedBrowsers WHERE BugId = '$bugId'");
$sth2->setFetchMode(PDO::FETCH_OBJ);
$sth2->execute();
$i = 1;
while($row2 = $sth2->fetch()){
if($i = 1){
echo $row2->browser;
}else{
echo ', ' . $row2->browser;
}
$i++;
}
}
My tables are as follows:
1) "Bugs" - this table has one row for each bug listed.
2) "AFfectedBrowsers" - this table houses all of the affected browsers for a particular bug. This table has a relationship with the "Bugs" table via the bugId column in the "AffectedBrowsers" table.
Note: I do realize that incrementing the $i could be done in a for loop instead of an if/else.
UPDATED: I need just one row per bug and i'm guessing add a column in the result set that has all of the affected browsers for that bug listed.

Answer 1

SELECT * FROM Bugs
INNER JOIN AffectedBrowsers ON Bugs.Id = AffectedBrowsers.BugId
LIMIT 5
Is that what your looking for?

Answer 2

SELECT * FROM Bugs
LEFT JOIN AffectedBrowsers
ON Bugs.BugId = AffectedBrowsers.BugId
LIMIT 5
If you want to list bugs, even if there are no affected browsers. By the way, you should get into the habit of listing out what columns you wan't to retrieve data from.

Answer 3

SELECT *
FROM Bugs
INNER JOIN
(SELECT BugId, GROUP_CONCAT(Browser) Browsers FROM AffectedBrowsers GROUP BY BugId) Aff
ON Bugs.Id = Aff.BugId

Answer 4

The other answers are good. However, if you need to limit the number of bugs and don't care about the number of affected browsers, use this:
SELECT *
FROM AffectedBrowsers
WHERE BugID IN ( SELECT id FROM Bugs LIMIT 5 )
Note that this is a real subquery. But, unlike your code, it is contained in one single statement and should still be faster.