php mysql foreach repeats twice - php

Hi i am using foreach in php oops to output data from the mysqlbut each data outputs twice please check my code and help it i have tried but no correct result
Here is the code below i have used
class getdata extends db{
public function getdata(){
$sql = "SELECT * FROM users";
$results = $this->connect()->query($sql);
$numrows = $results->num_rows;
if($numrows > 0){
while($row = $results->fetch_assoc()){
$data[] = $row;
}
return $data;
}
else{
echo 'no values';
}
}
}
class showusers extends getdata{
//show users
public function showusers(){
$datas = $this->getdata();
foreach($datas as $data){
echo $data['id'].'<br>';
echo $data['name'].'<br>';
}
}
}
$showusers = new showusers();
$showusers->showusers();

Don't give your function the same name as your class.
With $showusers = new showusers(); you are already executing the showusers function.
To cite php.net:
For backwards compatibility with PHP 3 and 4, if PHP cannot find a __construct() function for a given class, it will search for the old-style constructor function, by the name of the class.
Source:https://www.php.net/manual/en/language.oop5.decon.php
So your function showusers() is treated as a constructor for your showusers class and therefore is executed twice. Once when you create an object of the class and once when you call the method.

your code is a bit convoluted I'd suggest passing the database connection object rather than extending continiously.
In this case your constructor showUsers() outputs a list of users. therefore it repeats because you are calling this function twice.
$showusers = new showusers(); // prints users
$showusers->showusers(); // prints users again
move your display function
class showusers extends getdata{
$data;
//initialize
public function showusers(){
$this->data = $this->getdata();
}
//show users
public function displayUsers(){
foreach($this->data as $data){
echo $data['id'].'<br>';
echo $data['name'].'<br>';
}
}
}
$showusers = new showusers();
$showusers->displayUsers();

Related

Accessing class properties in PHP OOP

I am new in PHP OOP and was wondering if someone could help me with this.
I have a basic class with one method which returns data from database. Currently I am calling the method which displays everything inside the function.
Here is my class Definition:
class Products{
//properties
public $familyName = "";
public $familyProduct = "";
//Methods
public function getFamily($catId){
global $conn;
$sql = "SELECT * FROM product_family WHERE catID = '$catId'";
$result = $conn->query($sql);
if($result->num_rows > 0){
while($row = $result->fetch_assoc()){
echo "<li>".$row['familyName']."</li>";
echo "<li>".$row['familyProduct']."</li>";
}
}
}
}
Here is how I call the method:
$Products = new Products;
$Products->getFamily( 4 );
This works however, how can I assign each data coming from database ( ex familyName, familyProduct ) into variables inside class implementation and then access them individually where ever I need to. Something like this:
$Products = new Products;
$Products->familyName;
$Products->familyProduct;
I have empty properties but I am not sure how can I assign values to them coming from the loop and then return them each.
Thanks,
There are view things I would change in your Code.
Don't make Properties public use use Getters and Setters.
This will protect you Object from being used the wrong way e.g. now you can't change the familyName from outside: $products->familyName = "some value" because this would make the data of the object corrupt.
global $conn; is a no go in OOP use the construct of the Object,
in your case $products = new Products($conn);
Now you can set a Cat ID $products->setCatId(4); and read the result
$familyName = $products->getFamilyName(); or $familyProduct = $products->getFamilyProduct();
If you have more than one result you will get an array, if catId will always result one row you can delete this part. If you learn more about OOP you will find out that the hole SQL stuff can be done with a separate Object, but this is off Topic.
class Products
{
// Properties
protected $conn;
protected $catId;
protected $familyName;
protected $familyProduct;
public function __construct($conn)
{
$this->conn = $conn;
}
// set Cat ID and get date
public function setCatId($catId)
{
$this->catId = (int) $catId;
$this->getDate();
}
public function getCatId()
{
return $this->catId;
}
// get Family Name
public function getFamilyName()
{
return $this->familyName;
}
// get Family Product
public function getFamilyProduct()
{
return $this->familyProduct;
}
// get date
protected function getDate()
{
$sql = "SELECT * FROM product_family WHERE catID = '$this->catId'";
$result = $this->conn->query($sql);
// Default if no result
$this->familyName = null;
$this->familyProduct = null;
// if one Result
if ($result->num_rows == 1)
{
$row = $result->fetch_assoc();
$this->familyName = $row['familyName'];
$this->familyProduct = $row['familyProduct'];
}
if ($result->num_rows > 1)
{
$this->familyName = [];
$this->familyProduct = [];
while ($row = $result->fetch_assoc())
{
$this->familyName[] = $row['familyName'];
$this->familyProduct[] = $row['familyProduct'];
}
}
}
}

Why isn't the array I return in my __construct class available in the following function?

I've written a class which in the construct accesses the db and gets a list of names. These names go into an associative array e.g. ('name' => 'id').
i.e. the point is to pass in the name to get back an ID:
$id = names::nameToId('some name');
print $id;
// prints int
The problem is when I try and return the array from the construct I get an error:
Notice: Undefined variable: nameArray in (etc)
Here is the code so far:
class nameToId {
public $nameArray;
private $mysqli;
public function __construct($mysqli) {
...
while($row = mysqli_fetch_assoc($res)) {
$nameArray[$row['name']] = $row['id'];
}
return $nameArray;
}
static public function nameToId($name) {
$nameId = $nameArray[$name];
return $nameId;
}
}
$namesToId = new nameToId($mysqli);
$nameId = $namesToId::nameToId('some name');
echo $nameId;
Why doesn't $nameArray get passed to nameToId()? I'm new to classes, and I thought by declaring $nameArray as public when I first create the class that it would make it available. I have also tried to make it global even though I know that is not good form but even still it didn't work.
Because you cannot return anything from a constructor. Any return value is being ignored and just goes into the aether. $nameArray is a local variable and is not shared in any other scope, i.e. you can't access it in nameToId. Further, since nameToId is static, it won't have access to data from any non-static methods like __construct to begin with.
You probably want something like this:
class nameToId {
public $nameArray;
private $mysqli;
public function __construct($mysqli) {
...
while ($row = mysqli_fetch_assoc($res)) {
$this->nameArray[$row['name']] = $row['id'];
}
}
public function nameToId($name) {
return $this->nameArray[$name];
}
}
$namesToId = new nameToId($mysqli);
echo $namesToId->nameToId('some name');
Fix your code:
class nameToId {
public static $nameArray;
private $mysqli;
public function __construct($mysqli) {
$this->mysqli = $mysqli;
$sql = 'SELECT id, name FROM teams';
$res = mysqli_query($this->mysqli,$sql);
while($row = mysqli_fetch_assoc($res)) {
self::$nameArray[$row['name']] = $row['id'];
}
}
static public function nameToId($name) {
$nameId = self::$nameArray[$name];
return $nameId;
}
}
$namesToId = new nameToId($mysqli);
$nameId = $namesToId::nameToId('some name');
echo $nameId;

Passing mysql result $row to another method in a class

I Have a Main class Employee which fetches Employees Details,Passed Inputs it fetches mysql results and RETURNS into a associate array into $row.
public function Result(){
$this->IsEmptyCheck();
$this->ConnectDb();
$this->QueryDb();
$this->RowCount();
$this->IfEmployeeFound();
}
public function IfEmployeeFound(){
if ($this->row_cnt > 0)
{
while ($row = $this->result->fetch_assoc()){
return($row);
}
}else{echo "No Results" ;}
}
public function CustomhtmlTabledisplay($row){
foreach ( $row as $key => $value ) {
echo .....
echo "<td>".$value['employee_name']."</td>\n";
echo "<td>".$value['age']."</td>\n";
echo "<td>".$value['familydetails']."</td>\n";
echo .....
}
}
I am running the below php call calling the employee class and executing above functions in it like this.
$check = new Employee($employeeid);
$check->Result()->CustomhtmlTabledisplay();
$check->CloseDb();
How can i achieve it ?
I would like to fetch the data by passing the mysql returned rows array from
IfEmployeeFound() into CustomhtmlTabledisplay();
I would like to display employee details by executing this type of query
$check->Result()->CustomhtmlTabledisplay();
(If I understood). For doing next - by executing this type of query:
$check->Result()->CustomhtmlTabledisplay();
You need return $this in end of every method for chaining methods. And store need data in property-fields of your Main Class.
EDIT
If you want use your class like this
$check->CustomhtmlTabledisplay(($check->Result());
change class methods to:
public function Result(){
$this->IsEmptyCheck();
$this->ConnectDb();
$this->QueryDb();
$this->RowCount();
return $this->IfEmployeeFound();
}
public function IfEmployeeFound(){
$out = array();
if ($this->row_cnt > 0){
while ($row = $this->result->fetch_assoc())
$out[] = $row;
}
return empty($out)? null: $out;
}
public function CustomhtmlTabledisplay($rows){
if($rows){
foreach ( $rows as $row) {
echo .....
echo "<td>".$row['employee_name']."</td>\n";
echo "<td>".$row['age']."</td>\n";
echo "<td>".$row['familydetails']."</td>\n";
echo .....
}
}
}
You can use
require_once (employee.php); //employee is the file where you have the methods
And instance the class employee

Use external array inside class PHP

I have this function (in file functions.php) that returns me a list of the users in a database.
function db_listar_usuarios(){
$link = db_connect();
$query = "select * from usuarios" or die("Problemas en el select: " . mysqli_error($link));
$result = $link->query($query);
$myArray = array();
while($row = mysqli_fetch_assoc($result)) {
$myArray[$row['nombre']] = $row;
//print_r($myArray); // for debugging
}
return $myArray;
//print_r($myArray);
}
and i want to use it in a Class that is in another file (server.php)
<?php
include('functions.php');
class Server {
private $contacts = db_listar_usuarios(); //<-- this doesn't work =(
...
}
What can I do to make this code work?
Thanks!
You can't call a function in that position. When you declare class variables, they must be constants (see: http://www.php.net/manual/en/language.oop5.properties.php).
You need to use the constructor to do that.
<?php
include('functions.php');
class Server {
private $contacts;
function __construct(){
$this->contacts = db_listar_usuarios();
}
}
PHP does not allow to set dynamic values in the property declaration. You cannot call a function in that place.
You have to move that function call to the constructor, which is called automatically when an instance of that class is created:
private $contacts;
public function __construct() {
$this->contacts = db_listar_usuarios();
}

Changing mysql result to "Class" with methods?

I have seen these codes:
$result = $db->result($query);
$rows = $result->fetchAll();
how can I do similar effect? ($result contains methods?)
I think this is what you are looking for:
<?php
class test{
private $value = 0;
function foo(){
$this->value = 1;
return $this;
}
function bar(){
$this->value = 2;
echo $this->value;
}
}
$test = new test();
$result = $test->foo();
$result->bar();
?>
By having the method return itself, you can chain them together in this fashion.
Strictly speaking, you're asking about OOP in PHP, in which case, this is a reasonable example:
class HasResultMethod
{
public function result( $query )
{
return new HasFetchAllMethod();
}
}
class HasFetchAllMethod
{
public function fetchAll(){}
}
// you have a variable with a result method that has one parameter.
$result = $db->result($query);
// that returns an object which has a fetchAll method.
$rows = $result->fetchAll();
You probably are dealing with some wrapper around PDO, a library to interface with databases. Their query methods will return a PDOStatement which has methods which will allow you to get results from the DB. result is either a typo, or it behaves in a very similar way.
I got it already. What a great hint Headspin
http://sandbox.phpcode.eu/g/147bd.php
<?php
class foo{
function bar(){
return $this;
}
function fetch(){
echo "yeah";
}
}
$foo = new foo();
$result = $foo->bar();
$result->fetch();
That is easy
$db is instance of class that returnes class, so when you say
$db->result($query);
$db will return object
e.g.
//this method is inside $db class
function result($query)
{
$result = new Result();
$result->rows = mysql_query...
return $result;
}
and when you say
$result->fetchAll();
that is method inside class Result that will fetch all rows saved inside $result->rows;
e.g.
//method inside Result class
function fetchAll()
{
//fetch rows inside variable $this->rows
}
So basically what you can do with ORM (object relational mapping), you can return Array of objects, each object will represent one record from db
e.g.
Class User
{
var $ID;
var $Name;
var $LastName;
var $Email;
function load($row)
{
$this->ID = $row["ID"];
... etc
}
function save()
{
$sql = "update tbl_users set Name=:Name, LastName=:LastName, Email=:Email where ID=:ID";
//then execute your query
}
}
so how to get list of objects, its easy
select all records and add them into array
$ar = new Array();
for($i = 0; $i < count($rows); $i++)
{
$r = new User();
$r->load($rows[$i]);
}
return $ar;
simple as that...

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