Fatal error while trying to call a method in constructor - php

Question

I am trying to write my own MVC Framework using this tutorial. Everything worked fine and i completed the tutorial with no issues.
However later i decided to use PDO (PHP Data objects) instead of mysql() functions for Database Operations. So i modified My sqlQuery.php file to use PDO istead of mysql functions.
sqlQuery.php
<?php
class SQLQuery {
private $_dbHandle;
private $_result;
/**
* Connects to database
*
* #param $address
* #param $account
* #param $pwd
* #param $name
*/
function connect($address, $account, $pwd, $name) {
try{
$this->_dbHandle = new PDO("mysql:host=$address;dbname=$name", $account, $pwd);
}catch (PDOException $e) {
die($e->getCode() . " : " . $e->getMessage());
}
}
/** Disconnects from database **/
function disconnect() {
$this->_dbHandle = null;
}
function get($whereClause = array()) {
$query = "select * from $this->_table";
if(is_array($whereClause) && count($whereClause)){
$query .= " where ";
foreach($whereClause as $column=>$value)
$query .= " $column = $value";
}else if(is_int($whereClause)){
$query .= " where id = $whereClause ";
}
return $this->query($query);
}
/**
* Custom SQL Query
*
* #param $query
* #return array|bool
*/
function query($query) {
$this->_result = $this->_dbHandle->query($query);
$this->_result->setFetchMode(PDO::FETCH_CLASS, $this->_model);
if (preg_match("/select/i",$query)) {
$result = array();
$numOfFields = $this->_result->rowCount();
if($numOfFields > 1){
while($result[] = $this->_result->fetch()){
}
}else{
$result = $this->_result->fetch();
}
return $result;
}
return true;
}
}
Now when In my Controller when i print $this->Item->get() I get all the results in my database as Objects of Items Model and $this->Item->get(2) gives me the item object with id=2 as expected.
However, I don't like the idea that my API needs to be to call an additional method get() to get the objects of the Items Model, Instead it makes more sense that when a Items Model is initialized i get the desired object and so my API can be $this->item->mycolumnName.
To achieve this i tried to move the get() call in the Models constructor like this :
model.php
<?php
class Model extends SQLQuery{
protected $_model;
function __construct() {
$this->connect(DB_HOST,DB_USER,DB_PASSWORD,DB_NAME);
$this->_model = get_class($this);
$this->_table = strtolower($this->_model)."s";
$this->get();
}
function __destruct() {
}
}
However this gives me a Fatal error
Fatal error: Maximum function nesting level of '256' reached, aborting! in /var/www/html/FitternityAssignment/library/sqlquery.php on line 59
I don't know what i have done wrong.

Answer 1

The issue is line 59: while($result[] = $this->_result->fetch()){
function query($query) {
$this->_result = $this->_dbHandle->query($query);
$this->_result->setFetchMode(PDO::FETCH_CLASS, $this->_model);
if (preg_match("/select/i",$query)) {
$result = array();
$numOfFields = $this->_result->rowCount();
if($numOfFields > 1){
while($result[] = $this->_result->fetch()){
}
}else{
$result = $this->_result->fetch();
}
return $result;
}
return true;
}
Let's narrow in on the issue:
while($result[] = $this->_result->fetch()){
}
Infinite loop.
When fetch() returns something, then it is added to $result, because $result is an array, and then of course it evaluates to true because the size of $result grows each time a fetched result is added.
$results = [];
while($row = $this->_result->fetch()){
$results[] = $row; // or whatever you need to do with the row
}
Might work. I say might because it depends on what $this->_result->fetch() returns when no results are left. I'll assume false or null, in which case the above will work, because when there are no more results then fetch() will return null or false and $row will then evaluate to false.