Flexible function for updating DB records from PHP - php

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;
}

Answer 2

Something like this should work:
function generateUpdateQuery($table, $fields, $where) {
$updateFields = array();
foreach ($fields as $k => $v) {
$updateFields[] = $k.' = \''.$v.'\'';
}
$sqlQuery = 'UPDATE '.$table.
' SET '.implode(', ', $updateFields).
' WHERE '.implode(' AND ', $where);
return $sqlQuery;
}
echo generateUpdateQuery('table_name',
array(
'field_a' => '10',
'field_b' => 'hello',
'field_c' => 'world'),
array(
'id=12',
'datetime > NOW()')
);
Keep in mind that this is a simple example without any security check. Something like PDO would be recommended.
Moreover, if you're looking for something more robust and flexible you should give a look to a ORM system, like Doctrine