Question

Is there any way to make the below-given code reusable for different tables, e.g. using foreach? So, how to send and use arrays of column names and values? Any example is highly appreciated.

<?php
    include_once 'include/DatabaseConnector.php';
    if(isset($_POST['flightNum'])) {
        $flightNum=$_POST['flightNum'];
        $from=$_POST['from'];
        $STADate=$_POST['STADate'];
        $query = 'UPDATE flightschedule 
                  SET frm="'.$from.'",STADate="'.$STADate.'"
                  WHERE flightNum="'.$flightNum.'"';
        DatabaseConnector::ExecuteQuery($query);
        echo '1';
    } else { 
        echo '0'; 
    }
?>

UPDATE: What if I don’t know column names apriori? How to create flexible UPDATE statement?

Answer 1

you can convert your code into a reusable function. for example.

function updateDB($tableName, $flightNum, $from, $STADate) {
    include_once 'include/DatabaseConnector.php';
    $query = 'UPDATE ' . $tableName 
              SET frm="'.$from.'",STADate="'.$STADate.'"
              WHERE flightNum="'.$flightNum.'"';
    $execute = DatabaseConnector::ExecuteQuery($query);
    return $execute;
}

and to use it

if(isset($_POST['flightNum']) {
    $update = updateDB('flightschedule', $_POST['flightNum'], $_POST['from'], $_POST['STADate']);
    echo $update;
}

Update:

I want to send an array of column names to the function ‘updateDB’.
Let’s say these are column names for SET and WHERE parts of UPDATE
statement. And then I could use FOREACH, but I need some example for
this.

this is how you can do it.

function updateDB($tableName, $columns, $where) {
    //do some validation here to check if proper data is being passed like
    if(!isarray($columns)) {
        throw new Exception('argument two $columns should be an associative array');
    }
    include_once 'include/DatabaseConnector.php';
    $query  = 'UPDATE ' . $tableName;
    foreach($columns as $column => $data) {
        $query .= ' SET ' . $column . ' = ' . $data . ', ';
    }
    //remove last comma from the update query string
    $query = substr($query, 0, -1);
    $query .= ' WHERE ' . $where['column'] . ' = ' . $where['value'];
    $execute = DatabaseConnector::ExecuteQuery($query);
    return $execute;
}

and to use it.

if(isset($_POST['flightNum']) {
    $columns = array(
        'frm' => $_POST['frm'],
        'STADate' => $_POST['STADate']
    );
    $where = array(
        'column'=> 'flightNum', 
         'value' =>  $_POST['flightNum']
    );
    $update = updateDB('flightschedule', $columns, $where);
    echo $update;
}