[SOLVED] First Half of $result <split> Second Half of $result

[Yves]

$sql = "SELECT * FROM table  WHERE var = ".$string."";
$result = $obj_db->select($sql);

 

Assume $result is 21 rows in total and I want to display the first half of those rows in a left column and the second half of those rows in a right colomn. $result show be spilt in two.

 

something like this...:

 

$sql = "SELECT * FROM table  WHERE var = ".$string."";

if($pos=="left") {

$result = *Let-Me-Be-The-First-Half-Of*($sql);

}

if($pos=="right") {

$result = *Let-Me-Be-The-Second-Half-Of*($sql);

}

 

How can I make $result be 11 the first rows when $pos is set to 'left'?

How can I make $result be 10 the last rows when $pos is set to 'right'?

 

I hope I explained what I want clear enough.

[Orio]

You could do something like this:

 

<?php

echo "<table><tr>";

$all = mysql_num_rows($result);
$half = floor($all / 2);


echo "<td width=\"50%\">";
for($i=0; $i < $half; $i++)
{
$row=mysql_fetch_array($result);
//print what you want
}
echo "</td><td width=\"50%\">";
while($row=mysql_fetch_array($result)
{
$row=mysql_fetch_array($result);
//print what you want2
}

?>

 

 

Orio.

[NArc0t1c]

Ahh, Orio beat me to it, here is mine anyway.

Well so you want the array in two halves?

 

Try this.

<?php

$sql = "SELECT * FROM table  WHERE var = ".$string."";
$result = mysql_fetch_assoc($obj_db->select($sql));
$number = 0;
$first = array();
$end = array();
foreach ($result as $r) {
while ($number <= (count($result)/2)) {
$number++;
$first[] = $r; }
while($number > (count($result)/)) {
$number++;
$end[] = $r; }
}

?>

I don't know if it will work, but theory is there. (:

[Yves]

I'm actually writing a function.

 

If I would try methods suggested above I would end up writing double as much code.

 

However, this is what I tried...

 

<tr>

<td><?php echo Display($obj_db,0,left); ?></td>

<td><?php echo Display($obj_db,0,right); ?></td>

</tr>

 

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
$result = $obj_db->select($sql);
$all = mysql_num_rows($result);
$half = floor($all / 2);
if($pos == "left") {
	for($i=0; $i <= $half; $i++) {
	$row = mysql_fetch_array($result);
	}
}
if($pos == "right") {
	for($i=0; $i > $half; $i++) {
	$row = mysql_fetch_array($result);
	}
}
for($i=0; $i < $all; $i++) {
$maincat = $row[$i]['varCategory'];
// everything I need I can write once, right here.
// in the end it will display different data in both left and right column
echo $maincat;
}
}

 

This piece of code is incorrect though. And I still lack the knowledge to spot why it is. I bet someone here spots it instantly. 

[Yves]

I still need some help.

[rarebit]

Here's the phat hip way!

function halves($sql)
{
$result = $obj_db->select($sql);
$all = mysql_num_rows($result);
$l = "<td>";
$r = "<td>";
for($i=0;$i<$all;$i++)
{
	$flag = (($i % 2) == 0) ? 'l' : 'r';
	if($flag == 'l')
	{
		$l .= mysql_fetch_array($result);
	}
	else
	{
		$r .= mysql_fetch_array($result);
	}
}
$l .= "</td>";
$r .= "</td>";
return "<tr>".$l.$r."</tr>";
}
echo  halves("SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC");

I've not checked it but, hey ho!

[rarebit]

Sorry, I don't know how to read??

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
$result = $obj_db->select($sql);
$all = mysql_num_rows($result);
$half = floor($all / 2);
$start = 0;
if($pos == "left") { $start = $half;	}

for($i=$start; $i <= $half; $i++) {
	$row = mysql_fetch_array($result);
}

for($i=0; $i < $all; $i++) {
$maincat = $row[$i]['varCategory'];
// everything I need I can write once, right here.
// in the end it will display different data in both left and right column
echo $maincat;
}
}

[MmmVomit]

<?php
$sql = "SELECT field FROM table;"; // use your sql query here

$result = mysql_query($sql);

$rows = Array();

$num_rows = mysql_num_rows($result);
while($rows[] = mysql_fetch_assoc($result)){;} // fetch all rows into an array

?>
<table>
<?php
for($i = 0; i < ($num_rows / 2) + ($num_rows % 2); $i++)
{
?>
  <tr>
    <td><?=$rows[$i]['field']?></td>
    <td><?=(isset($rows[2 * $i]) ? $rows[2 * $i]['field'] : " ")?></td>
  </tr>
<?php
}
?>
</table>

 

Something like that should do it.  It should be easy enough to turn into a function.

 

I don't have PHP on this computer, so I apologize for any bugs.

 

[Yves]

rarebit

I tried your code, but it didn't work. Changed it to this:

 

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
$result = $obj_db->select($sql);
$all = count($result);
$half = floor($all / 2);

if($pos == "left") { $start = 0; $end = $half; }
if($pos == "right") { $start = $half; $end = $all; }

for($i=$start; $i <= $end; $i++) {
	$row = mysql_fetch_array($result);
}

for($i=0; $i < $all; $i++) {
$maincat = $row[$i]['varCategory'];
// everything I need I can write once, right here.
// in the end it will display different data in both left and right column
echo $maincat;
}
}

 

but I get a

 

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in config.inc.php on line 256

[rarebit]

Not checked it, but this looks better:

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
$result = $obj_db->select($sql);

//$all = count($result);
$all = mysql_num_rows($result);

$half = floor($all / 2);

if($pos == "left") { $start = 0; $end = $half; }
if($pos == "right") { $start = $half; $end = $all; }

for($i=$start; $i <= $end; $i++) {
	//$row = mysql_fetch_array($result);
	$row[] = mysql_fetch_array($result);
}

for($i=0; $i < $all; $i++) {
	$maincat = $row[$i]['varCategory'];
	// everything I need I can write once, right here.
	// in the end it will display different data in both left and right column
	echo $maincat;
}
}

[Yves]

I can see why it would work. Though, instead, it gave us an extra warning.

 

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in config.inc.php on line 249

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in config.inc.php on line 256

[rarebit]

I don't use a db object like you, so my query statement is like this:

$result = mysql_query($sql, $conn)

your doing a query with this:

$result = $obj_db->select($sql);

which actually looks more like your selecting a database???

Do you see what I mean, otherwise show more of your database code...

[Yves]

I see what you mean, and managed to make it work.

 

Though, the right column shows exactly the same content as the left column. I'll be a little bit more specific. My $result counts 27 rows (14&13), default. I edited the function to shows 14 results in the left column, and 13 in the right.

 

14: row 0 -> row 13

13: row 14 -> row 26

 

Notice the changes at if($pos == "right"):

 

<?php

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
   	$result = mysql_query($sql);
$all = mysql_num_rows($result);
$half = floor($all / 2);

if($pos == "left") { $start = 0; $end = $half; }
if($pos == "right") { $start = $half+1; $end = $all-1; }

for($i=$start; $i <= $end; $i++) {
$row[] = mysql_fetch_array($result);
}

for($i=0; $i < $all; $i++) {
$maincat = $row[$i]['varCategory'];
// everything I need I can write once, right here.
// in the end it will display different data in both left and right column
echo $maincat;
echo "<br>";
}
}

?>

 

The only thing it didn't do is change the content of the row[] array. Both left and right column start with the same stuff.

 

 

[rarebit]

I'm not keen, but:

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
   	$result = mysql_query($sql);
$all = mysql_num_rows($result);
$half = floor($all / 2);

if($pos == "left") { $start = 0; $end = $half; }
if($pos == "right") { $start = $half+1; $end = $all-1; }

for($i=0; $i <= $all; $i++)
{
	if(($i >= $start )&& ($i <= $end))
	{
		//$row[] = mysql_fetch_array($result);
		$row = mysql_fetch_array($result);
		echo $row['varCategory'];
	}
}
}

 

Are you sure that query works?

[Yves]

Yes, that one works exactly the same. But both left and right show same results. (appart from left column having 1 item more, as should)

 

here's a picture:

 

[rarebit]

lollipop!

for($i=0; $i <= $all; $i++)
{
	$row = mysql_fetch_array($result);

	if(($i >= $start )&& ($i <= $end))
	{
		echo $row['varCategory'];
	}
}

[rarebit]

P.S. I'm not keen because it's called twice, therefore making two mysql calls, and wastes iterations through the array and fetch_array... argh!!!!

[Yves]

Very nice, rarebit!

 

thanks a bunch.

 

Here's what I think is completely right:

 

<?php

function Display($obj_db="",$ParentID,$pos) 
{
$sql = "SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC";
   	$result = mysql_query($sql);
$all = mysql_num_rows($result);
$half = floor($all / 2);

if($pos == "left") { 
	// $start
	$start = 0;
	// $end
	if ($all % 2 == 1) { // when $all is uneven
	$end = $half;
	}
	if ($all % 2 == 0) { // when $all is even
	$end = $half-1;
	}
}
if($pos == "right") { 
	// $start
	if ($all % 2 == 1) { // when $all is uneven
	$start = $half+1;
	}
	if ($all % 2 == 0) { // when $all is even
	$start = $half;
	}
	// $end
	$end = $all-1;
}

for($i=0; $i <= $all; $i++)
{
	$row = mysql_fetch_array($result);

	if(($i >= $start )&& ($i <= $end))
	{
		echo $row['varCategory'];
		echo "<br>";
	}
}
}

?>