setting php boolean to FALSE not working - php

Question

I have no records in a table called assessment
I have a function:
function check_assessment_record($p_id, $a_id, $c){
$dataexistsqry="SELECT * FROM assessments WHERE (pupil_id=$p_id && assessblock_id=$a_id)" ;
$resultt = $c->query($dataexistsqry);
if ($resultt->num_rows > 0) {
echo '<p>set $de = true</p>';
$de=TRUE;
}else{
echo '<p>set $de = false</p>';
$de=FALSE;
}
return $de;
$dataexists->close();
}; //end function
I call the function thus:
$thereisdata = check_assessment_record($pupil_id, $assessblock_id, $conn);
However my function is printing out nothing when I was expecting FALSE. It prints out true when there's a record.
When I get the result in $thereisdata I want to check for if its TRUE or FALSE but its not working.
I looked at the php manual boolean page but it didn't help

Answer 1

It seems that you are passing the database connection as an object using the variable $c in your function parameter. This tells me that you would greatly benefit by creating a class and using private properties/variables. Also, there are many errors in your code that shows me what you are trying to achieve, some errors are the way you are closing your db connection using the wrong variable, or how you place the close connection method after the return, that will never be reached.
Anyway, I would create a database class where you can then call on specific functions such as the check_assessment_record() as you wish.
Here's how I would redo your code:
<?php
class Database {
private $conn;
function __construct() {
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
// Create connection
$this->conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($this->conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
}
function check_assessment_record($p_id, $a_id) {
$sql = "SELECT * FROM assessments WHERE (pupil_id=$p_id && assessblock_id=$a_id)";
$result = $this->conn->query($sql);
if ($result->num_rows > 0) {
echo '<p>set $de = true</p>';
$de = TRUE;
} else {
echo '<p>set $de = false</p>';
$de = FALSE;
}
return $de;
}
function __destruct() {
$this->conn->close();
}
}
$p_id = 1;
$a_id = 2;
$db = new Database();
$record = $db->check_assessment_record($p_id, $a_id);
var_dump($record);
?>

Answer 2

are you using PDO's correctly?
A call for me would normally look like;
$aResults = array();
$st = $conn->prepare( $sql );
$st->execute();
while ( $row = $st->fetch() ) {
//do something, count, add to array etc.
$aResults[] = $row;
}
// return the results if there is, else returns null
if(!empty($aResults)){return $aResults;}
if you didnt want to put the results into an array you could just check if a column is returned;
$st = $conn->prepare( $sql );
$st->execute();
if(! $st->fetch() ){
echo 'there is no row';
}

Answer 3

Here is the code
function check_assessment_record($p_id, $a_id, $c){
$dataexistsqry="SELECT * FROM assessments WHERE (pupil_id=$p_id && assessblock_id=$a_id)" ;
$resultt = $c->query($dataexistsqry);
if ($resultt->num_rows > 0) {
echo '<p>set $de = true</p>';
$de=TRUE;
}else{
echo '<p>set $de = false</p>';
$de=FALSE;
}
return $de;
$dataexists->close();
}; //end function
You can check the return value using if else condition as
$thereisdata = check_assessment_record($pupil_id, $assessblock_id, $conn);
if($thereisdata){ print_f('%yes data is present%'); }
else{ print_f('% no data is not present %'); }
The reason is , sometime function returning Boolean values only contain the true value and consider false value as null , that's why you are not printing out any result when data is not found.
Hope this will help you. Don't forget to give your review and feedback.