how to loop through PHP code and MySQL? - php

Question

How do I use the PHP loop through the query instead of putting all the result into an array then looping through the array
The way I use array and loop is like this:
<?php $userInfos = $qry->querySelect( SQL CODE HERE );
foreach($userInfos as $uInfo)
{
$fName = $uInfo['fName'];
$lName = $uInfo['lName'];
$gender = $uInfo['gender'];
?>
First name is: <? echo $fName; ?> and Last name is <? echo $lName; ?>.
<?php } ?>
I wanted to know better insight on how PHP loop through the query is better than array. Please redirect me to some example or possibly with MySQL code included.
How can I convert the above php code to be more efficient if I am pulling millions of record?
Thanks so much!.

Answer 1

You can do a simple loop with mysqli_fetch_row()
http://php.net/manual/en/mysqli-result.fetch-row.php

Answer 2

It looks like you need to use something other than the querySelect function (which appears to be returning an array).
Maybe the $qry object has some other function that will return you a statement handle you can fetch from, like the normal mysqli_ and PDO interfaces provide.
It looks to me like $qry is from a homegrown MySQL library "wrapper" class, which exposes a limited subset of the functions. If that object doesn't provide a way to get a statement handle, you may need to add the appropriate functions to the object definition, or abandon that and just use mysqli or PDO.
There's lots of examples of how to do that. With PDO, our first cut (before we add error checking and exception handling) might look something like this:
$sql="SELECT t.name FROM really_big_table t";
$sth=$dbh->prepare($sql);
$sth->execute();
while ($row = $sth->fetch(PDO::FETCH_ASSOC) ) {
echo "<br>Name is: ". htmlentities($row['name']);
}
$sth->close();
Reference: http://php.net/manual/en/pdostatement.fetch.php

Answer 3

I do the following:
//DB Query getData
$q_getData = "SELECT `stuff`, `moreStuff`, `otherStuff` FROM `table`";
$rsgetData = mysqli_query($DBi, $q_getData) or die(mysqli_error($DBi));
$row_rsgetData = mysqli_fetch_assoc($rsgetData);
$rows_rsgetData = mysqli_num_rows($rsgetData);
if($rows_rsgetData>0) {
do {
echo $row_rsgetData['stuff'] . ' ' . $row_rsgetData['moreStuff'] . '<br>';
echo $row_rsgetData['otherStuff'];
} while ($row_rsgetData = mysqli_fetch_assoc($rsgetData));
$rows = mysqli_num_rows($rsgetData);
if($rows > 0) {
mysqli_data_seek($rsgetData, 0);
$row_rsgetData = mysqli_fetch_assoc($rsgetData);
}
mysqli_free_result($rsgetData);
};
That runs the query and loops through each row until there are no rows left - only if there are rows returned in the first place. Once it's all finished it frees up the connection.