I found this error in the error log file "Unsupported operand types in (and then it shows the directory and file which gave the error)". Then it says on line 28. Line 28 on my PHP page reads:
$start = ($page -1) * 5;
This might not be enough information, but please give feedback on what else I should provide to help me out.
Use the intval function on the variable $page. Also, you may want to check the $start variable for a negative value.
Like so:
function getScenes($page)
{
$total = 0;
$pages = 0;
$start = (intval($page) - 1) * 5;
if ($start < 0) {
$start = 0;
}
$query = $this->db->query("SELECT count(iId) as total FROM scenes ");
$scene = $query->result();
$total = $scene[0]->total;
if ($total) {
$pages = ceil($total / 5);
}
$q = $this->db->query("SELECT * FROM scenes ORDER BY iId DESC LIMIT $start,5");
$result = $q->result();
if (count($result)) {
return array(
'pages' => $pages,
'scenes' => $result
);
} else {
return false;
}
}
Related
I'm currently trying to make some pagination work, but without any success.
The first query I'm executing is to grab all the data needed: so first result should be on the first page, second result on the second and so on... But I'm always getting the first result. Although I copied the query into phpmyadmin to manualy set the query and there it showed me the right results.
Here's the code where everything is happening. I'm stuck why it won't work.
$page = isset($_GET['page']) ? $_GET['page'] : 1;
$limit = 1;
$start = 0;
$query = $db->prepare("SELECT * FROM `users` LIMIT $limit OFFSET $start");
$query->execute();
$result = $query->fetchAll(PDO::FETCH_OBJ);
$count = count($result);
$query2 = $db->prepare("SELECT * FROM `users`");
$query2->execute();
$result2 = $query2->fetchALL(PDO::FETCH_OBJ);
$count2 = count($result2);
// Pagination
$total = ceil($count2 / $limit);
if ($page > 1) {
$start = ($page - 1) * $limit;
}
if ($page != $total) {
$next_page = '<li>»</li>';
} else {
$next_page = '<li class="disabled">»</li>';
}
if ($page > 1) {
$previous_page = '<li>«</li>';
} else {
$previous_page = '<li class="disabled">«</li>';
}
What am I doing wrong?
You are doing nothing with $page. $start is always 0 in the query.
You're going to need to define how many records you want per page, then multiply that by $page -1, e.g.
$start = ($page - 1) * $records_per_page;
I currently have a method inside my "car class" that display the car:
static function getCars(){
$autos = DB::query("SELECT * FROM automoviles");
$retorno = array();
foreach($autos as $a){
$automovil = automovil::fromDB($a->marca, $a->modelo, $a->version, $a->year, $a->usuario_id, $a->kilometraje, $a->info,
$a->hits, $a->cilindrada, $a->estado, $a->color, $a->categoria, $a->precio, $a->idAutomovil);
array_push($retorno, $automovil);
}
return $retorno;
}
In my index.php I call that function
foreach(car::getCars() as $a){
That allows me to display the info this way ( of course inside the foreach I have a huge code with the details I'll display.
Is there a way to implement a pagination to that thing so I can handle 8 cars per page, instead of showing all of them at the same page?
You can add a $limit and $page parameter on your function so that it will only return a maximum of $limit number of items starting from $limit * $page(or will call it the $offset). You also need to add a function to get the total number of rows you have for automoviles table.
static function getCars($page = 0, $limit = 8){
$offset = $limit * max(0, $page - 1);
//replace this with prepared statement
$autos = DB::query("SELECT * FROM automoviles LIMIT $offset, $limit");
$retorno = array();
foreach($autos as $a){
$automovil = automovil::fromDB($a->marca, $a->modelo, $a->version, $a->year, $a->usuario_id, $a->kilometraje, $a->info,
$a->hits, $a->cilindrada, $a->estado, $a->color, $a->categoria, $a->precio, $a->idAutomovil);
array_push($retorno, $automovil);
}
return $retorno;
}
static function getTotal()
{
//query to get total number of rows in automoviles table
}
In your index.php do this:
foreach(car::getCars((isset($_GET['page']) ? $_GET['page'] : 1)) as $a){
...
}
and add the pagination links.
$total = car::getTotal();
if($total > 8) {
for($i = 1; $i <= intval(ceil(1.0 * $total / $limit)); $i++) {
echo '' . $i . ';
}
}
I am trying to set up a jqgrid and I am having difficulty in constructing the controller that generates the json data to populate the grid. I am using codeigniter 2.0+ and I am not sure how to build the query for php in codeigniter.
I followed this guid under "Loading Data -> JSON Data" for the jqgrid. I also consulted codeigniter docs on data selection. The thing is I am not sure how to write the second query to sort and limit according to the jqgrid paramiters. Here is my controller.
public function applicantdata(){
$page = $this->input->get('page');// get the requested page
$limit = $this->input->get('rows');// get how many rows we want to have into the grid
$sidx = $this->input->get('sidx');// get index row - i.e. user click to sort
$sord = $this->input->get('sord');// get the direction
if(!$sidx){ $sidx =1; }
$this->db->select('*');
$this->db->from('applicant');
$this->db->join('transaction', 'transaction.applicant_id = applicant.id');
$query = $this->db->get();
$count = $query->num_rows();
$limit = 10;
if( $count > 0 ) {
$total_pages = ceil($count/$limit);
} else {
$total_pages = 0;
}
if ($page > $total_pages){ $page=$total_pages; }
$start = $limit*$page - $limit; // do not put $limit*($page - 1)
//NOT SURE HOW TO DO THIS IN CODEIGNITER ENVIRONMENT
//$SQL = "SELECT a.id, a.invdate, b.name, a.amount,a.tax,a.total,a.note FROM invheader a, clients b WHERE a.client_id=b.client_id ORDER BY $sidx $sord LIMIT $start , $limit";
//$result = mysql_query( $SQL ) or die("Couldn t execute query.".mysql_error());
$result = $query->result_array();
$responce->page = $page;
$responce->total = $total_pages;
$responce->records = $count;
$i=0;
foreach ($result as $myrow){
$responce->rows[$i]['id']=$myrow['id'];
$responce->rows[$i]['cell']=array($myrow['id'],$myrow['firstname'],$myrow['lastname'],$myrow['amount'],$myrow['status']);
$i++;
}
echo json_encode($responce);
}
With the above code, the grid is populating and its is working to a greater extent. Only thing is the pagination stuff not working properly in that the data on page one shows when I move to page 2, 3, etc.
Her is the final working thing. For anyone who may need it.
public function applicantdata(){
$page = $this->input->get('page');// get the requested page
$limit = $this->input->get('rows');// get how many rows we want to have into the grid
$sidx = $this->input->get('sidx');// get index row - i.e. user click to sort
$sord = $this->input->get('sord');// get the direction
if(!$sidx){ $sidx =1; }
$this->db->select('firstname');
$this->db->from('applicant');
$this->db->join('transaction', 'transaction.applicant_id = applicant.id');
$query = $this->db->get();
$count = $query->num_rows();
if( $count > 0 ) {
$total_pages = ceil($count/$limit);
} else {
$total_pages = 0;
}
if ($page > $total_pages){ $page=$total_pages; }
$start = $limit*$page - $limit; // do not put $limit*($page - 1)
$this->db->select('*');
$this->db->from('applicant');
$this->db->join('transaction', 'transaction.applicant_id = applicant.id');
$this->db->order_by("applicant.id", $sord);
$this->db->limit($limit, $start);
$query2 = $this->db->get();
$result = $query2->result_array();
$responce->page = $page;
$responce->total = $total_pages;
$responce->records = $count;
$i=0;
foreach ($result as $myrow){
$responce->rows[$i]['id']=$myrow['id'];
$responce->rows[$i]['cell']=array($myrow['id'],$myrow['firstname'],$myrow['lastname'],$myrow['amount'],$myrow['status']);
$i++;
}
echo json_encode($responce);
}
This should be a fairly straight forward question. I am getting a Warning: mysql_num_rows() expects parameter 1 to be resource, boolean error and I can't figure out the correct syntax. Using mysqlerror I am getting You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-5, 5' .
Any help would be great. The code is part of a pagination that I am adding.
Snippet of affected code
<?php
//Number of items to display per page
$perpage = 5;
if(isset($_GET["page"]))
{
$page = intval($_GET["page"]);
}
else
{
$page = 1;
}
$calc = $perpage * $page;
$start = $calc - $perpage;
$result = mysql_query("select * from products Limit $start, $perpage");
$rows = mysql_num_rows($result);
echo mysql_error();
if($rows)
{
$i = 0;
while($post = mysql_fetch_array($result))
{
?>
$start cannot be negative (and it is). You should make sure, that $page is not less than 1. This should fix your problem:
<?php
//Number of items to display per page
$perpage = 5;
$page = isset($_GET['page']) ? intval($_GET['page']) : 1;
if ($page < 1)
{
$page = 1;
}
$calc = $perpage * $page;
$start = $calc - $perpage;
$result = mysql_query("select * from products Limit $start, $perpage");
$rows = mysql_num_rows($result);
echo mysql_error();
if($rows)
{
$i = 0;
while($post = mysql_fetch_array($result))
{
?>
when you're using LIMIT the value of the starting point should be greater or equal to zero.
LIMIT
Ok what i'm wanting to do is split a number ($row['count']) into 5, this is easy enough if you want equal numbers:
$sum = ($row['count'] / 5);
$fsum = floor($sum);
but I want each number to be different and still add up to total ie $row['count'] how can this be achieved?
Update:
If this helps its to be used to update 5 rows in a database:
$query = "SELECT * FROM foo";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result)) {
$sum = ($row['count'] / 5);
$fsum = floor($sum);
$id = $row['id'];
$update = "UPDATE foo SET foo1='$fsum', foo2='$fsum', foo3='$fsum', foo4='$fsum', foo5='$fsum' WHERE id='$id'";
mysql_query($update);
}// while
so ideally the $update query would be something like:
$update = "UPDATE foo SET foo1='$fsum1', foo2='$fsum2', foo3='$fsum3', foo4='$fsum4', foo5='$fsum5' WHERE id='$id'";
This is my take:
function randomize($sum, $parts) {
$part_no = count($parts);
$continnue_counter = 0;
while (count(array_unique($parts)) != $part_no) {
$changing = array_rand($parts, 2);
if (($parts[$changing[0]] - 1) == 0 || ($parts[$changing[1]] - 1) == 0) { // don't let them go under 1
++$continnue_counter;
// sometime one element get everything and others even out on 1
// just throw away everything you got so far and start over
if ($continnue_counter > 10) {
$parts = setup($sum, $part_no);
$continnue_counter = 0;
}
continue;
}
$continnue_counter = 0;
$signum = mt_rand(0, 100) % 2 ? 1 : -1;
$delta = $signum * mt_rand(1, min($parts[$changing[0]] - 1, $parts[$changing[1]] - 1)); // -1 to make sure they don't go under 0
$parts[$changing[0]] += $delta;
$parts[$changing[1]] -= $delta;
}
return $parts;
}
function setup($sum, $part_no) {
$parts = array_fill(0, $part_no, (int)($sum / $part_no));
// acount for the reminder of (int) cast
$reminder = $sum - array_sum($parts);
while ($reminder) {
$parts[array_rand($parts)] += 1;
--$reminder;
}
return $parts;
}
$part_no = 5;
$sum = 42;
$parts = randomize($sum, setup($sum, $part_no));
var_export($parts);
print array_sum($parts)
Update:
I've added a version that introduces a little more entropy.
Update2:
The more random one had a tendency to decrement everything to 1 except one part, added an explicit detection to deal with this. Still the algorithm behind it has unknown termination time.