OPP mysqli_query() expect two parameters... - php

Question

I am trying to learn object oriented programming.
The problem what I have is how to add link under mysqli_query() inside the class.
In procedural style I just create a $variable with connection details and then using it inside the mysqli_query($variable, $sql) etc.
In my class I have function connect() which will connect to database and return true but Haw can I use it inside my mysqli_query() please? please see the code here:
<?php
class DB {
protected $db_name = 'OOP_forum';
protected $db_user = 'Marcel';
protected $db_pass = *****;
protected $db_host = 'localhost';
public function connect() {
$connection = mysqli_connect($this->db_host, $this->db_user, $this->db_pass);
mysqli_select_db($connection, $this->db_name);
return true;
}
public function processRowSet($rowSet, $singleRow = false) {
$resultArray = array();
while($row = mysqli_fetch_assoc($rowSet)) {
arraypush($resultArray, $row);
}
if($singleRow==true) {
return $resultArray[0];
}else {
return $resultArray; }
}
public function select ($table, $where, $column = '*') {
$sql = "SELECT $column FROM $table WHERE $where";
$result = mysqli_query($sql);
if(mysqli_num_row($result) == 1 ){
return $this->processRowSet($result, true);
} else
{ return $this->processsRowSet($result);
}
}
public function update ($data, $table, $where) {
foreach ($data as $column->$value) {
$sql = "UPDATE $table SET $column = $value WHERE $where";
mysqli_query($sql) or die(mysqli_error());
}
return true;
}
public function delete ($table, $column, $where) {
$sql = "DELETE FROM $table WHERE $column = $where";
if (query($sql)=== TRUE) {
echo "Record Deleted sucessfully";
}else {
echo "Error deleting record: " . $connection->error;
}
}
public function insert($data, $table) {
$columns = "";
$values = "";
foreach ($data as $column->$value) {
$columns .= ($columns == "") ? "": ", " ;
$columns .= $column;
$values .= ($values == "") ? "" : ", ";
$values .= $value;
}
$sql = "insert into $table ($columns) values ($values)";
mysqli_query($sql) or die(mysqli_error());
return mysqli_insert_id();
}
}
?>

Answer 1

Before trying to learn OOP programming you have to learn basic OOP syntax.
In order to do so forget for a while about creating your own classes and learn how to use already made ones. So, first of all learn how to use mysqli. Which is already a class.
Better yet, learn PDO instead, as, unlike mysqli, it's already a ready to use database access class, with it you don't need functions like processRowSet, for example.