if Row1 = Value 1, Update other rows

Question

I have a little php script that goes to mySql database.

I want to look, before i insert a new record in the database, if the number (value1) equals a record in the datab

Answer 1

Why go through the trouble of counting the rows found for a particular phone number? Just check for $data->phone_number !== null and then execute an update query blindly

$stmt = $pdo->prepare('UPDATE table SET longitude = :longitude, latitude = :latitude, timestamp = :timestap WHERE id = :id');
if ($stmt->execute(array(':longitude' => $data->longitude,':latitude' => $data->latitude,':timestamp' => $data->timestamp,':id' => $data->phone_number)))
{
    echo 'Updated';
}
else
{
    echo 'Couldn\'t update';
}

Or better yet: set $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); and update within a try-catch block, so you can check why the update query failed and respond accordingly. If your db engine supports it, you can use $pdo->rollBack(); when an update has occurred when it shouldn't, too:

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
try
{
    $stmt = $pdo->prepare('UPDATE table SET longitude = :longitude, latitude = :latitude, timestamp = :timestap WHERE id = :id');
    $stmt->execute(array(':longitude' => $data->longitude,':latitude' => $data->latitude,':timestamp' => $data->timestamp,':id' => $data->phone_number));
}
catch(PDOException $e)
{
    $pdo->rollBack();//undo any changes
    echo $e->getMessage();
}