Add or update MySQL - mysql

Question

I don't know how to proceed to do the following thing on my specific table.
Let's say I have the following table param, with 3 columns tck, label, value . tck is my primary key.
The data are coming once everyday. I would like to update the value of the existing tck, and if the data sent contain a new tck, I would like to add it to the table...
I hope I'm clear enough... Thank you for your help.
The code I'm using is the following one :
<?php try {
$bdd = new PDO('mysql:host='.$_ENV['localhost'].';dbname=eip_tasks','root'); } catch(Exception $e) {
die('Erreur : '.$e->getMessage()); }
$data = $_POST['field1'];
$phpArray = json_decode($data, true); foreach ($phpArray as $u) {
//$req = $bdd->prepare('INSERT INTO param (tck, label, value) VALUES(:tck, :label, :value)');
$req = $bdd->prepare('UPDATE param SET value=:value WHERE tck=:tck');
$req->execute(array(
':tck'=>$u['tck'],
':value'=>$u['value']
)); } ?>
Here is the code I'm using now :
<?php
try
{
$bdd = new PDO('mysql:host='.$_ENV['localhost'].';dbname=eip_tasks','root');
}
catch(Exception $e)
{
die('Erreur : '.$e->getMessage());
}
$data = $_POST['field1'];
$phpArray = json_decode($data, true);
$sourceTck = array();
foreach ($phpArray as $u) {array_push($sourceTck, $u['tck']);
$req = $bdd->prepare("INSERT INTO param (tck, label, value) VALUES (:tck, :label, :value) ON DUPLICATE KEY UPDATE value=:value");
$req->execute(
array(
':tck'=>$u['tck'],
':label'=>$u['label'],
':value'=>$u['value']
)
);
}
if(count($sourceTck) > 0){
$sourceTckClause = implode("," , $sourceTck);
$req = $bdd->prepare("DELETE FROM param WHERE tck NOT IN ($sourceTckClause)");
$req->execute();
}
?>

Answer 1

Use ON DUPLICATE KEY syntax to update the row instead of insert (if tck was exist):
$req = $bdd->prepare("
INSERT INTO param (tck, label, value)
VALUES
(:tck, :label, :value)
ON DUPLICATE KEY UPDATE value=:value
");
Update: Also don't forget to bind :label. As your comment, To delete a data which would be in the table and not in the source, You should push source tck values to an array and then run a delete query where NOT IN your array:
$sourceTck = array();
foreach ($phpArray as $u) {
array_push($sourceTck, $u['tck']);
$req = $bdd->prepare("
INSERT INTO param (tck, label, value)
VALUES
(:tck, :label, :value)
ON DUPLICATE KEY UPDATE value=:value
");
$req->execute(
array(':tck'=>$u['tck'], ':label'=>$u['label'], ':value'=>$u['value'])
);
}
I found this answer useful to prepare and bind tck values, But for small solution, you can convert array values to int to prevent sql injection in this case:
if(count($sourceTck) > 0){
$sourceTckClause = implode("," , array_map('intval', $sourceTck));
$bdd->query("DELETE FROM param WHERE tck NOT IN ($sourceTckClause)");
}

Answer 2

What you want to do is called an upsert or merge. MySQL does support it.
INSERT INTO param VALUES (:tck, :label, :value)
ON DUPLICATE KEY UPDATE value = :value
-- change :label as well? , label = :label