Check duplicate person in database

Hi!
I'm developing a form with a external database. The primary key is id ,but we have another field, dni (identity card) and is unique.
I need check if that person inserted in my database was already inserted or not.
How I can check it? I'm beginner in Joomla.

Thank you!
Bye!!

Hi hv,

Try a Custom code, check with a php code if he already exists.

BN

Hi BN,
Should I have a custom code before or after DB SAVE?
Don't I need reading my database?
And, do you have a code example?

Thank you for your answer!!

Hi hv,

I would switch the db save for a custom action, so I'll do it with some like:
(p.s. I'm assuming that your user is logged)

<?php
$user = JFactory::getUser();
$con=mysqli_connect("server, "username", 
"password", "databasename");
// Check connection
if (mysqli_connect_errno())
{
echo "Error: " . mysqli_connect_error();
}
$userExists= mysqli_query($con,"SELECT * FROM 
"tablename" WHERE dni=".$user->get("id")."");

if (!$userExists) { 
$query= mysqli_query($con,"INSET INTO "tablename" ('dni', 'field1', 'field2', 'field3', 'field4', 'fieldN') VALUES ('".$user->get("id")."',"".$form->data["field1"]."","".$form->data["field2"]."","".$form->data["field3"]."","".$form->data["field4"]."","".$form->data["fieldN"]."")");
 }
?>

I dind't test the code, so please, test it and debug if needed.

BN

BNDragon

Good idea, but you can use "Event Switcher", custom Code for check if already exist the user with the Joomla API for less code.

$db = JFactory::getDbo();
$user = JFactory::getUser();
 
$query = $db->getQuery(true);
$query= 'SELECT * FROM #__tablename WHERE id='. $user->get("id");
$db->setQuery($query);
$db->query();
$num_rows = $db->getNumRows();

if ($num_rows==0){
    return "success";
    }else{
    return "fail";
}

In success option, you load the action "DB Save" and de Fail Option you load the action "Event Loop"

See the image http://prntscr.com/5esdgc

Try, good day

Hi inocampo,

That's a great idea, I didn't remember that😉

BN