PHP mysql_fetch_array

At what point does it stop being true? The while is a loop that while Existing rows in the query will remain true once the query runs out of data the loop ends ... it's very simple.

What are the data you iterate? It depends on what you request in your query; the index can be literal or numeric. and will read them by lines.

How does this code work?

while($row = $query->fetch(PDO::FETCH_ASSOC))
{#Mientrastenga registros devuelve true
    #lectura para la fila actual
    echo $row['indice Litera de columna'];
    echo '<br>'; #Salto de linea
}

Well, basically what this line does:

while($row = $query->fetch(PDO::FETCH_ASSOC)) { //Code }

It is to return the data of each record that the query that you did previously obtained.

The While cycle stops once the fetch stops sending data.

You can access the data in the following way

while($row = $query->fetch(PDO::FETCH_ASSOC)) {
//usa este si estas obteniendo los datos en forma de objeto 
echo $row->nombredelcampo;
//usa este si estas obteniendo los datos en una matriz
echo $row["nombredelcampo"];
 }

P.d. replace "fieldname" with the names of the fields you want to manipulate from your table.

What happens is:

- while($row=mysql_fetch_array($result) {  //Code } =  forma procedural
- while($row = $query->fetch(PDO::FETCH_ASSOC)) { //Code } esto es POO

That it would be the same has while($row=mysql_fetch_assoc($result)) procedurally

What the While does, is that it executes as long as the condition is true.

Greetings.

In my opinion and criteria, the easiest way to consult a table in the database is as follows:

$connection = new PDO("mysql:host=localhost; dbname=database", "admin", "12345");
$connection -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$connection -> exec("SET CHARACTER SET utf8");

$age = 18;

$stmt = $connection -> prepare("SELECT * FROM USER WHERE AGE = :age");
$stmt -> bindParam(':age', $age);
$stmt -> execute();
$rows = $stmt -> fetchAll(PDO::FETCH_OBJ);
$stmt -> closeCursor();

foreach($rows as $user)
{
    echo $user -> NAME;
}

$connection = null;

From the point of view of security and also from the point of view of using less code and be as efficient as possible. I hope the above code is helpful, if you have any questions, leave me a comment and I will gladly answer.