Two While Loops, Second Returns Empty Array? - php

Question

I'm experimenting with MySQLi and using the following code to check differences for how I should approach my array formatting/usage for fetch_array(MYSQLI_ASSOC);
here is my code:
include "Database.php";
$ArrayQuery = $mysqli->query("SELECT * FROM accountinformation");
while ($ArrayResults = $ArrayQuery->fetch_array(MYSQLI_ASSOC))
{
echo count($ArrayResults);
echo "<br>";
}
echo "<br><br><bR><br>";
$Empty = array();
while ($ArrayResult = $ArrayQuery->fetch_array(MYSQLI_ASSOC))
{
foreach ($ArrayResult AS $ArrayRes)
{
$Empty[] = $ArrayRes;
}
}
print_r($Empty);
The problem is, that i'm using the same Variable for my while loop, the first one returns 3 then 3 Which is expected.
But the problem is, with my second query; it returns a blank array
array( ) when print_r();
and when I do:
while ($ArrayResult = $ArrayQuery->fetch_array(MYSQLI_ASSOC))
{
print_r($ArrayResult);
}
For my Second while loop, it returns nothing for output.
I have checked my variables $ArrayResults and $ArrayResult are not duplicates, they are in fact unique.
Why is my second while loop returning nothing when my first one is working?
Update
When I produce a second query into the mixture with a different starting variable:
$ArrayQuer = $mysqli->query("SELECT * FROM accountinformation");
and modify my second while loop:
while ($ArrayResult = $ArrayQuer->fetch_array(MYSQLI_ASSOC))
{
print_r($ArrayResult);
}
I get the expected output? So is it a case of MySQLi not allowing the same parameters to be used twice throughout the script?

Answer 1

mysqli_data_seek
Adjusts the result pointer to an arbitrary row in the
result
while ($ArrayResults = $ArrayQuery->fetch_array(MYSQLI_ASSOC))
{
echo count($ArrayResults);
echo "<br>";
}
echo "<br><br><bR><br>";
mysqli_data_seek($ArrayQuery,0); // Addition Made Here
$Empty = array();
while ($ArrayResult = $ArrayQuery->fetch_array(MYSQLI_ASSOC))
{
foreach ($ArrayResult AS $ArrayRes)
{
$Empty[] = $ArrayRes;
}
}
print_r($Empty);
To re-use an already fetched array; you should use mysqli_data_seek(); (Notice I have added it above your `$Empty Variable) This should be the problem.
See the manual here:
http://us.php.net/manual/en/mysqli-result.data-seek.php
Think of this scenario; Why would you re-buy something you already own?
Fits perfectly in your case