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@NogDogDec 14.2015 — #Is it safe to assume $con has been successfully defined/set before you try to use it here? (Just asking: sometimes it's the simple, silly little things.)
How I might write up the queries in order to capture some debug info:
(breaking up the SQL into multiple lines often helps you locate a problem, as the DB error message will often mention the offending line number)
Trying to select from double select. doesnt work?
trying to select from a double select but it doesnt work. I get Warning: mysqli_query(): Couldn’t fetch mysqli. this is the code:
[code=php]
<?php
$result = mysqli_query($con, “SELECT u.* FROM users AS u JOIN (SELECT visitorid FROM visitors AS v WHERE v.userid = $userid ORDER BY last_visit DESC LIMIT 6) AS v1 ON u.user_id = v1.visitorid”);
?>
<table style=”width:100%”>
<?php
while($row = mysqli_fetch_array($result))
{
$cuser = $_SESSION[‘user’];
$favorite = $row[‘username’];
echo “username: $favorite”; //works
$res2 = mysqli_query($con, “SELECT * FROM favorites WHERE favorite=’$favorite’ AND cuser=’$cuser'”); //Warning: mysqli_query(): Couldn’t fetch mysqli
$row2 = mysqli_fetch_array($res2);
$favorite = $row2[‘favorite’];
echo “Favorite= $favorite”;
?>
…..
…..
…..
</table>
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@NogDogDec 14.2015 — #Is it safe to assume $con has been successfully defined/set before you try to use it here? (Just asking: sometimes it's the simple, silly little things.)How I might write up the queries in order to capture some debug info:
[code=php]
<?php
ini_set('display_errors', true); // set to false in production
error_reporting(E_ALL);
$sql = <<<EOD
SELECT u.*
FROM users AS u
JOIN (
SELECT visitorid
FROM visitors AS v
WHERE v.userid = $userid
ORDER BY last_visit DESC LIMIT 6
) AS v1 ON u.user_id = v1.visitorid
EOD;
$result = mysqli_query($con, $sql);
if($result == false) {
throw new Exception(mysqli_error($con).PHP_EOL.$sql);
// at some point you want to wrap all this in a try/catch block
// so that you can more gracefully handle any DB exceptions
}
[/code](breaking up the SQL into multiple lines often helps you locate a problem, as the DB error message will often mention the offending line number)