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I have this helper method which job should be to prepare pagination data in order to retrieve it on controller...
Basically this is the code which happens in helper
if (!isset($_GET['page'])) {
$_GET['page'] = 1;
}
if (!isset($_GET['per_page'])) {
$_GET['per_page'] = 5;
}
$results = $ci->$model->get('', $_GET['per_page'], $_GET['page']);
And this is my model which should return data
public function get($tableName = "", $limit = null, $start = null)
{
if ($tableName == "") {
$tableName = $this->table;
}
if ($limit != null && $start != null) {
// problem is here with limit and start which returns wrong data
$this->db->limit($limit, $start);
$query = $this->db->get($tableName);
var_dump($query->result());
die();
}
} else {
$query = $this->db->get($tableName);
}
return $query->result();
}
Problem is that data returned from model isn't correct and i can't figure out how to get properly data based on page number and items per page....
So in my case if i request data with paramas $_GET['page'] = 1 and $_GET['per_page'] = 5 it will return 5 records, but starting with record 2 till record 6. So my question is how to properly request give me let say 5 records on starting page 1 and then give me another 5 records on page 2 ETC....
If you need any additional information please let me know and i will provide. Thank you
The problem lies within your $start variable. You should remember that when using getting the first the 5 records, you should use an offset 0 instead 1. Counting starts from 0 remember :)
The code should be
public function get($tableName = "", $limit = null, $start = null)
{
if ($tableName == "") {
$tableName = $this->table;
}
if ($limit != null && $start != null) {
// problem is here with limit and start which returns wrong data
//$this->db->limit($limit, $start);
// use this instead
$this->db->limit($limit, ( $start - 1 ) * $limit );
$query = $this->db->get($tableName);
var_dump($query->result());
die();
}
} else {
$query = $this->db->get($tableName);
}
return $query->result();
}
This is working example try to do like this: https://www.formget.com/pagination-in-codeigniter/
I am unable to understand how to fix this notice. It gives a undefined index on a $_GET[' '] and I cannot set a isset() as it'll brake the query and code.
class.php
private $perPage = 8;
private $startPage = 0;
public function latestArticles()
{
if($_GET['page'] <= 1) NOTICE ERROR <-- is here on the $_GET['page'];
$this->startPage = 0;
else
$this->startPage = $_GET['page'] * $this->perPage - $this->perPage;
$this->db->setAttribute(PDO::ATTR_EMULATE_PREPARES, FALSE);
$sth = $this->db->prepare("SELECT * FROM articles ORDER BY id DESC LIMIT ?, ?");
$sth->execute(array($this->startPage, $this->perPage));
$data = $sth->fetchAll();
return $data;
}
And this code which sets the header if the button is clicked(next or previous button). If you first load the page, there is no header it loads like ex: www.site.com/ so it gives the error as there are no $_GET['page'] being set, but I cannot get around this issue.. this here is how I am printing the data being retrieved by the function.
index.php
<?php
if(!isset($_GET['page']))
$page = 1;
else
$page = $_GET['page'];
foreach($latestArticles as $article)
{
$title = $article['title'];
echo ''.$title.'';
}
$prev = $page-1;
$next = $page+1;
echo "
<a class='nxt_prevButton' href='?page=$prev'>previous page</a>
<a class='nxt_prevButton' href='?page=$next'>next page</a>
";
?>
failed attempts
I have set the isset() and empty() but it doesn't allow the code to work which is a next and previous button for more results, 8 results per page. (notice goes away but code (query) stops working).
What is a way to get around this, by fixing the code? WITHOUT using error_reporting(0); ?
You definitely need to use isset, it's just a matter of working out the logic.
I think, if I understand this right, that you could do this:
if(!isset($_GET['page']) || $_GET['page'] <= 1)
$this->startPage = 0;
else
$this->startPage = $_GET['page'] * $this->perPage - $this->perPage;
So if $_GET['page'] isn't set, startPage will be 0.
I'm porting some old PHP code from mysql to MySQLi, and I've ran into a minor snag.
Is there no equivalent to the old mysql_result() function?
I know mysql_result() is slower than the other functions when you're working with more than 1 row, but a lot of the time I have only 1 result and 1 field. Using it lets me condense 4 lines into 1.
Old code:
if ($r && mysql_num_rows($r))
$blarg = mysql_result($r, 0, 'blah');
Desired code:
if ($r && $r->num_rows)
$blarg = $r->result(0, 'blah');
But there is no such thing. :(
Is there something I'm missing? Or am I going to have to suck it up and make everything:
if ($r && $r->num_rows)
{
$row = $r->fetch_assoc();
$blarg = $row['blah'];
}
The following function fully replicates the mysql_result() function, and returns false when you are out-of-bounds on your request (empty result, no row of that number, no column of that number). It does have the added benefit that, if you don't specify the row, it assumes 0,0 (one less value to be passed). The function allows for the numerical offset of the field or the field name.
function mysqli_result($res,$row=0,$col=0){
$numrows = mysqli_num_rows($res);
if ($numrows && $row <= ($numrows-1) && $row >=0){
mysqli_data_seek($res,$row);
$resrow = (is_numeric($col)) ? mysqli_fetch_row($res) : mysqli_fetch_assoc($res);
if (isset($resrow[$col])){
return $resrow[$col];
}
}
return false;
}
PHP 5.4 now supports function array dereferencing and 7.0 supports a null coalescing operator, which means you can simply do this:
$value = $r->fetch_assoc()['blah'] ?? false;
or even more generic variant where you don't need to supply the column name,
$value = $r->fetch_row()[0] ?? false;
note that you don't even need the if ($r && $r->num_rows) condition.
You can do this by fetching an object instead of an array.
$mysqli->query("SELECT email FROM users WHERE userid = 'foo'")->fetch_object()->email;
function db_result($result,$row,$field) {
if($result->num_rows==0) return 'unknown';
$result->data_seek($row);
$ceva=$result->fetch_assoc();
$rasp=$ceva[$field];
return $rasp;
}
Well, you can always shorten it to something like this:
if ($r && $r->num_rows)
list($blarg) = $r->fetch_row();
But that might be as good as you're going to get.
I suggest you to add this line to Cris' solution in order to be able to get a result by both doing db_result('mytable.myfield) and db_result('myfield') since it is the default behavior of the original mysql_result function.
function db_result($result,$row,$field) {
if($result->num_rows==0) return 'unknown';
$result->data_seek($row);
$ceva=$result->fetch_assoc();
return (isset($ceva[$field])?$ceva[$field]
:(strpos($field,'.')?$ceva[substr($field,strrpos($field,'.')+1)]:''));
}
I use the following function to replace mysql_result()
function mysqli_result($result, $iRow, $field = 0)
{
if(!mysqli_data_seek($result, $iRow))
return false;
if(!($row = mysqli_fetch_array($result)))
return false;
if(!array_key_exists($field, $row))
return false;
return $row[$field];
}
I ended up using a custom function using procedural style:
function mysqli_result($res, $row, $field=0) {
mysqli_data_seek($res, $row);
return mysqli_fetch_array($res)[$field];
}
Reference: https://www.sitepoint.com/community/t/change-mysql-result-to-mysqli/190972/6
You don't need mysql_result() or any similar function.
If you would like to access any column from any row in the result set, the best way is to fetch all into an array using mysqli_fetch_all().
$data = $result->fetch_all(MYSQLI_BOTH);
$var1 = $data[0]['column']; // column from the first row
$var2 = $data[1][2]; // third column from the second row
To prevent access to non-existent values, you can use the null-coalesce operator and provide default value. e.g. $data[1][2] ?? null;.
As of PHP 8.1, mysqli also offers method called fetch_column(). You can use it if you only want to fetch a single value from the result.
$value = $mysqli->query("SELECT email FROM users WHERE userid = 'foo'")->fetch_column(0);
If you select only ONE field in the query and you only expect a single returned data of a selected field, then this works:
function mysqli_datum($result)
{
if ($result->num_rows == 0)
return;
$result->data_seek(0);
$row=$result->fetch_row();
return $row[0];
}
Here's an adaptation of Mario Lurig's answer using a mysqli_result object instead of the procedural version of mysqli.
/**
* Accepts int column index or column name.
*
* #param mysqli_result $result
* #param int $row
* #param int|string $col
* #return bool
*/
function resultMysqli(mysqli_result $result,$row=0,$col=0) {
//PHP7 $row can use "int" type hint in signature
$row = (int)$row; // PHP5 - cast to int
if(!is_numeric($col) ) { // cast to string or int
$col = (string)$col;
} else {
$col = (int)$col;
}
$numrows = $result->num_rows;
if ($numrows && $row <= ($numrows-1) && $row >=0) {
$result->data_seek($row);
$resrow = (is_numeric($col)) ? $result->fetch_row() : $result->fetch_assoc();
if (isset($resrow[$col])){
return $resrow[$col];
}
}
return false;
}
This is a good answer, from http://php.net/manual/es/class.mysqli-result.php
<?php
function mysqli_result($result,$row,$field=0) {
if ($result===false) return false;
if ($row>=mysqli_num_rows($result)) return false;
if (is_string($field) && !(strpos($field,".")===false)) {
$t_field=explode(".",$field);
$field=-1;
$t_fields=mysqli_fetch_fields($result);
for ($id=0;$id<mysqli_num_fields($result);$id++) {
if ($t_fields[$id]->table==$t_field[0] && $t_fields[$id]->name==$t_field[1]) {
$field=$id;
break;
}
}
if ($field==-1) return false;
}
mysqli_data_seek($result,$row);
$line=mysqli_fetch_array($result);
return isset($line[$field])?$line[$field]:false;
}
?>
I am generating unique id for my small application but I am facing some variable scope problem. my code-
function create_id()
{
global $myusername;
$part1 = substr($myusername, 0, -4);
$part2 = rand (99,99999);
$part3 = date("s");
return $part1.$part2.$part3;
}
$id;
$count=0;
while($count == 1)
{
$id;
$id=create_id();
$sqlcheck = "Select * FROM ruser WHERE userId='$id';";
$count =mysql_query($sqlcheck,$link)or die(mysql_error());
}
echo $id;
I dont know which variable I have to declare as global
That doesn't look like a variable scope problem, it looks like a simple variable assign problem:
$count=0;
while($count == 1)
{
This block will clearly never execute.
Further, please use a boolean with a good name when doing boolean checks. It reads so much cleaner. i.e.:
function isUniqueUserID($userIDToCheck)
{
$sqlcheck = "Select * FROM user WHERE userId='$userIDToCheck';";
$resource = mysql_query($sqlcheck)or die(mysql_error());
$count = mysql_fetch_assoc($resource);
if( count($count) > 0)
{return false;}
return true;
}
$userIDVerifiedUnique = false;
while(! $userIDVerifiedUnique )
{
$userIDToCheck = create_id();
$userIDVerifiedUnique = isUniqueUserID($userIDToCheck );
}
Note that mysql_query will use the last used connection if you don't specify a link:
http://us2.php.net/mysql_query
No need to make it global.
in adition to Zak's answer i'd pass the username into the function instead of using globals
function create_id($username)
{
$part1 = substr($username, 0, -4);
$part2 = rand (99,99999);
$part3 = date("s");
return $part1.$part2.$part3;
}
also
//$id; no need for this
$count=1; // this bit
while($count == 1) // not sure what's going on
{
//$id; again same thing no need for this
$id=create_id($myusername);
edit: now that i think of it: how do you expect to find "Select * FROM ruser WHERE userId='$id';"? A Select query is used to find something specific, your username is so random, i think the likely hood of actually successfully getting a record is 1 in a bajillion.
edit2 whoops, i see the whole point is to get a unique username... O_O
In addition to the others:
$count =mysql_query($sqlcheck,$link)or die(mysql_error());
mysql_query doesn't return a record count but, rather, a resource.
mysql_query
I'm porting some old PHP code from mysql to MySQLi, and I've ran into a minor snag.
Is there no equivalent to the old mysql_result() function?
I know mysql_result() is slower than the other functions when you're working with more than 1 row, but a lot of the time I have only 1 result and 1 field. Using it lets me condense 4 lines into 1.
Old code:
if ($r && mysql_num_rows($r))
$blarg = mysql_result($r, 0, 'blah');
Desired code:
if ($r && $r->num_rows)
$blarg = $r->result(0, 'blah');
But there is no such thing. :(
Is there something I'm missing? Or am I going to have to suck it up and make everything:
if ($r && $r->num_rows)
{
$row = $r->fetch_assoc();
$blarg = $row['blah'];
}
The following function fully replicates the mysql_result() function, and returns false when you are out-of-bounds on your request (empty result, no row of that number, no column of that number). It does have the added benefit that, if you don't specify the row, it assumes 0,0 (one less value to be passed). The function allows for the numerical offset of the field or the field name.
function mysqli_result($res,$row=0,$col=0){
$numrows = mysqli_num_rows($res);
if ($numrows && $row <= ($numrows-1) && $row >=0){
mysqli_data_seek($res,$row);
$resrow = (is_numeric($col)) ? mysqli_fetch_row($res) : mysqli_fetch_assoc($res);
if (isset($resrow[$col])){
return $resrow[$col];
}
}
return false;
}
PHP 5.4 now supports function array dereferencing and 7.0 supports a null coalescing operator, which means you can simply do this:
$value = $r->fetch_assoc()['blah'] ?? false;
or even more generic variant where you don't need to supply the column name,
$value = $r->fetch_row()[0] ?? false;
note that you don't even need the if ($r && $r->num_rows) condition.
You can do this by fetching an object instead of an array.
$mysqli->query("SELECT email FROM users WHERE userid = 'foo'")->fetch_object()->email;
function db_result($result,$row,$field) {
if($result->num_rows==0) return 'unknown';
$result->data_seek($row);
$ceva=$result->fetch_assoc();
$rasp=$ceva[$field];
return $rasp;
}
Well, you can always shorten it to something like this:
if ($r && $r->num_rows)
list($blarg) = $r->fetch_row();
But that might be as good as you're going to get.
I suggest you to add this line to Cris' solution in order to be able to get a result by both doing db_result('mytable.myfield) and db_result('myfield') since it is the default behavior of the original mysql_result function.
function db_result($result,$row,$field) {
if($result->num_rows==0) return 'unknown';
$result->data_seek($row);
$ceva=$result->fetch_assoc();
return (isset($ceva[$field])?$ceva[$field]
:(strpos($field,'.')?$ceva[substr($field,strrpos($field,'.')+1)]:''));
}
I use the following function to replace mysql_result()
function mysqli_result($result, $iRow, $field = 0)
{
if(!mysqli_data_seek($result, $iRow))
return false;
if(!($row = mysqli_fetch_array($result)))
return false;
if(!array_key_exists($field, $row))
return false;
return $row[$field];
}
I ended up using a custom function using procedural style:
function mysqli_result($res, $row, $field=0) {
mysqli_data_seek($res, $row);
return mysqli_fetch_array($res)[$field];
}
Reference: https://www.sitepoint.com/community/t/change-mysql-result-to-mysqli/190972/6
You don't need mysql_result() or any similar function.
If you would like to access any column from any row in the result set, the best way is to fetch all into an array using mysqli_fetch_all().
$data = $result->fetch_all(MYSQLI_BOTH);
$var1 = $data[0]['column']; // column from the first row
$var2 = $data[1][2]; // third column from the second row
To prevent access to non-existent values, you can use the null-coalesce operator and provide default value. e.g. $data[1][2] ?? null;.
As of PHP 8.1, mysqli also offers method called fetch_column(). You can use it if you only want to fetch a single value from the result.
$value = $mysqli->query("SELECT email FROM users WHERE userid = 'foo'")->fetch_column(0);
If you select only ONE field in the query and you only expect a single returned data of a selected field, then this works:
function mysqli_datum($result)
{
if ($result->num_rows == 0)
return;
$result->data_seek(0);
$row=$result->fetch_row();
return $row[0];
}
Here's an adaptation of Mario Lurig's answer using a mysqli_result object instead of the procedural version of mysqli.
/**
* Accepts int column index or column name.
*
* #param mysqli_result $result
* #param int $row
* #param int|string $col
* #return bool
*/
function resultMysqli(mysqli_result $result,$row=0,$col=0) {
//PHP7 $row can use "int" type hint in signature
$row = (int)$row; // PHP5 - cast to int
if(!is_numeric($col) ) { // cast to string or int
$col = (string)$col;
} else {
$col = (int)$col;
}
$numrows = $result->num_rows;
if ($numrows && $row <= ($numrows-1) && $row >=0) {
$result->data_seek($row);
$resrow = (is_numeric($col)) ? $result->fetch_row() : $result->fetch_assoc();
if (isset($resrow[$col])){
return $resrow[$col];
}
}
return false;
}
This is a good answer, from http://php.net/manual/es/class.mysqli-result.php
<?php
function mysqli_result($result,$row,$field=0) {
if ($result===false) return false;
if ($row>=mysqli_num_rows($result)) return false;
if (is_string($field) && !(strpos($field,".")===false)) {
$t_field=explode(".",$field);
$field=-1;
$t_fields=mysqli_fetch_fields($result);
for ($id=0;$id<mysqli_num_fields($result);$id++) {
if ($t_fields[$id]->table==$t_field[0] && $t_fields[$id]->name==$t_field[1]) {
$field=$id;
break;
}
}
if ($field==-1) return false;
}
mysqli_data_seek($result,$row);
$line=mysqli_fetch_array($result);
return isset($line[$field])?$line[$field]:false;
}
?>