How can I show database value in real time?

Question

I’m a beginner in php, let alone js. I would like to take a count of how many users are registered in my database, but in real time using ajax. I have tried in many ways, but without success. for now I have only in code:

$sql = "SELECT * FROM usuarios";
$query = mysql_query($sql);
$conta = mysql_num_rows($query);

the result that comes from $account is what I want to put in a <span id="users"</span> only if I simply put one echo $conta within span, it will not be in real time the value that will come out... "logica' would be, in a file have the query with the count of lines of the table users, and in another page that has the span keep requesting the value that comes from the variable $account.

What I need:

Show in real time using ajax the value of a string that counts how many rows are in the "users" table in a <span id="users"></span>

Answer 1

You can use Ajax, but it’s not quite in real time. In the example below, requests are called every 2 seconds (you can change the time to more or less, but the shorter the time, you can overload the server with requests followed in a short time. Evaluate that).

function ajx(){
   var ajax = new XMLHttpRequest(); // cria o objeto XHR
   ajax.onreadystatechange = function(){
      // verifica quando o Ajax for completado
      if(ajax.readyState == 4 && ajax.status == 200){
         document.getElementById("users").innerHTML = ajax.responseText; // atualiza o span
         setTimeout(ajx, 2000); // chama a função novamente após 2 segundos
      }
   }
   ajax.open("GET", "pagina.php"); // página a ser requisitada
   ajax.send(); // envia a requisição
}
ajx(); // chama a função

Substitute pagina.php by the page where you are doing the echo.

Answer 2

I’ll start by putting my finger on what I think is wrong.
What reason would anyone have to show only the amount of registrants?

I think I’m wrong.I think I want to count users with a given name if it is : "IS WRONG"

$sql = "SELECT * FROM usuarios";
$query = mysql_query($sql);
$conta = mysql_num_rows($query);

If I’m right, you’ll have some discretion to tell me... "CORRECT"
Put one in your html
<div id="user"></div>
and a field responsible for rescuing its criteria

<input type="text"  placeholder="Digite o nome da cidade"name="Campo" id="Campo" onchange="PgReal(this.value);/>

The function is executed OnChange When you change the value of the E field you will return the values : Pay attention to that = php? Field file name

$variavelCampoNome=$_GET['CampoNome'];
$sql = "SELECT * FROM usuarios WHERE `Coluna` LIKE '%$variavelCampoNome%'";
if ($Resultado = mysql_query($sql)){ // Se ele conseguir executar
$conta = mysql_num_rows($Resultado);//faz a contagem
if ($conta==0){ //se FOR IGUAL A ZERO
echo 'Nenhuma Informação encontrada com esse criterio';
}else{ //Mostra a quantidade SE FOR DIFERENTE DE ZERO
echo '<span id="users">.$conta</span>';
while($Linha = mysql_fetch_array($Resultado)) {

//Criterios para exibir 
$VariavelColuna=$Linha[ColunaExibir];
echo $VariavelColuna;

}

}

Now the function .

function PgReal(str) {

    if (str == "") {
return;
    } else { 
        if (window.XMLHttpRequest) {
            // code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {
            // code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function() {
            if (this.readyState == 4 && this.status == 200) {
                document.getElementById("user").innerHTML = this.responseText; //Copia a resposta Para o div id=user
            }
        };
        xmlhttp.open("GET","Arquivo.php?CampoNome="+str,true);//Exececuta o chamado usando o valor do campo que você colocou o botao ONCHANGE
        xmlhttp.send();
    }

}

I THINK THAT’S WHAT YOU REALLY WANTED. MORE INTERNET FOR THIS. EDIT HOW AND WHERE YOU FIND BEST! Good luck