use an array in column name query - php

Question

i want to query column names of a table, put in an array and then use that data in to a table for html,
well is like that
<?php
$ser='localhost';
$usr='root';
$pas='password';
$bsd='basedata';
$tab='contact';
try
{
$dbh = new PDO('mysql:host='.$ser.';dbname='.$bsd.'', $usr, $pas);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = $dbh->prepare("SHOW FIELDS FROM $tab ");
$query->execute();
echo "<tr>";
$i=0;
while ($dat = $query->fetch()) {
$nombre_columna[$i]=$dat[0];
echo "<th>".$nombre_columna[$i]."</th>";
$i++;
}
echo "</tr>\n";
$dbh = new PDO('mysql:host='.$ser.';dbname='.$bsd.'', $usr, $pas);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = $dbh->prepare("SELECT * FROM $tab");
$query->execute();
$j=$i;
$i=0;
while ($dat = $query->fetch()) {
echo "<tr>";
while ($i<$j) {
echo "<td>".$dat[$nombre_columna[$i]]."</td>";
$i++;
}
echo "</tr>\n";
}
$dbh=null;
?>
so when i run the code it shows onli the first row of the query but no more

Answer 1

I think you are misinterpreting the output. It is looping through every row in the table, but your problem is that the while ($i<$j) loop will only work the first time through because you keep incrementing the value of $i, so it will never be less than $j after the first iteration. You need to reset the value of $i on each iteration, not before the loop as you have it.
while ($dat = $query->fetch()) {
$i=0; // <-- This will fix it
echo "<tr>";
while ($i<$j) {
echo "<td>".$dat[$nombre_columna[$i]]."</td>";
$i++;
}
echo "</tr>\n";
}
If you looked at the source code, I would guess that you would see a bunch of these:
<tr></tr>
<tr></tr>
<tr></tr>
<tr></tr>