[Qt/Sql] SQL Authentification : what query execute ?

[Lesiok]

First of all in line 4 You are taking from database only one value (mdp) but in line 10 You are trying to read value number 2 from result. Lines 9 and 10 should looks like :

if( query.first() )//position on first record. if false then SELECT returns nothing
    if(query.value(0).toString() == password->text())

if( query.first() )//position on first record. if false then SELECT returns nothing
    if(query.value(0).toString() == password->text())

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[CR4SH]

Thanks you for your help, now, if pseudo AND pwd is correct, then it work. But, how to do for check for existing pseudo/ pwd in database, like any kind of authentication system, which query I need ?
I've read that, in PHP, we need to use something like :

<?php
$req = $bdd->prepare("SELECT COUNT(*) FROM profil WHERE pseudo = :pseudo");
$req->bindValue(':pseudo', $_SESSION['pseudo'], PDO::PARAM_STR);
$req->execute();
$nb = $req->fetchColumn();
if($nb == 0)
  echo 'Pseudo not found';
else
  // ...

<?php
$req = $bdd->prepare("SELECT COUNT(*) FROM profil WHERE pseudo = :pseudo");
$req->bindValue(':pseudo', $_SESSION['pseudo'], PDO::PARAM_STR);
$req->execute();
$nb = $req->fetchColumn();
if($nb == 0)
  echo 'Pseudo not found';
else
  // ...

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But i don't know how to do in Qt.

[Lesiok]

Exactly the same as in PHP. After all, your main tool is here SQL and not PHP or C++.

[CR4SH]

Yes but which function works the same as fetchColumn ? And what will be the type of $nb in case of Qt use ?

[CR4SH]

Does anyone can help me ? I really need help to do this ...

[Lesiok]

Think a little. In the first email you know how to read a value from the database and now not ?

QSqlQuery query;
query.prepare("SELECT COUNT(*) FROM profil WHERE pseudo = :pseudo");
query.bindValue(":pseudo", pseudo->text());
if(query.exec())
{
    query.first();
    if( query.value(0).toInt() == 0 )
    {//not found
    }
    else
    {//found
    }
}

QSqlQuery query;
query.prepare("SELECT COUNT(*) FROM profil WHERE pseudo = :pseudo");
query.bindValue(":pseudo", pseudo->text());
if(query.exec())
{
    query.first();
    if( query.value(0).toInt() == 0 )
    {//not found
    }
    else
    {//found
    }
}

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[CR4SH]

Thanks for your help, i finaly found how to do.