选择之后和之前在MySQL中使用MySql在相同的结果上插入结果

Question

Good evening, I have a problem when i select some data from table. So, first, i call a select that return the last row of the table. After this, i insert new data in that table, and now call that select again and give me the same result of the first select. What i want is, when i insert, the last select returns the data inserted. If i execute another select already give me the last value inserted. My code is written in PHP and i use the interface mysqli. I already use transactions, refresh, set the cahce of mysqli to 0 in php.ini. Thanks.

EDITED 2 : I make a test:

<?php
include 'conf.php';

$query="INSERT INTO assinante.comentarios (id_cmnt,id_user,comentario,now_data) values (null,4,'coiso',NOW());";
$res=  mysqli_query($link,$query);

$query="SELECT * FROM $db_assin.comentarios;";
$res=  mysqli_query($link,$query);
$linha = mysqli_fetch_assoc($res);
print_r($linha);

$query="INSERT INTO assinante.comentarios (id_cmnt,id_user,comentario,now_data) values (null,3,'ola',NOW());";
$res=  mysqli_query($link,$query);

$query="SELECT * FROM $db_assin.comentarios;";
$res=  mysqli_query($link,$query);
$linha = mysqli_fetch_assoc($res);
print_r($linha);

And it return:

Array ( [id_cmnt] => 29 [id_user] => 3 [comentario] => coiso [now_data] => 2014-01-29 02:10:24 ) Array ( [id_cmnt] => 29 [id_user] => 3 [comentario] => coiso [now_data] => 2014-01-29 02:10:24 )

It seems that save in buffer or something like this. If you can help i appreciate.

EDITED : The code

function getComentarios(){
    include 'conf.php';
    $query = 
    "   SELECT  utili.username, cmnt.comentario , cmnt.now_data , cmnt.id_cmnt
        FROM ".$db_assin.".comentarios cmnt, ".$db_assin.".utilizadores utili
        WHERE utili.id_user = cmnt.id_user
        ORDER BY cmnt.id_cmnt DESC
        LIMIT 1;"; 
    $resultado = mysqli_query($link,$query);
    if($resultado){
        $linha = mysqli_fetch_array($resultado);
        $json = json_encode($linha);
        echo $json;
    }
    else{
        echo mysqli_error($link);
    }
        mysqli_free_result($resultado);
}

function ins_comment($id_user,$comment){
    include 'conf.php';
    $data = date('Y-m-d H:i:s');
    mysqli_autocommit($link, FALSE);
    mysqli_query($link,"BEGIN");
    $query_ins = "INSERT INTO ".$db_assin.".comentarios (id_cmnt,id_user,comentario,now_data) "
            . "values (null,$id_user,'$comment',NOW());";
    if (!$res_ins = mysqli_query($link,$query_ins)){
        echo mysqli_error ($link);
        mysqli_rollback($link);
    }
    else{
        mysqli_commit($link);
    }
    mysqli_autocommit($link, TRUE);
    mysqli_refresh($link, MYSQLI_REFRESH_HOSTS);
    return $res_ins;
}

function comentar(){
    include 'conf.php';
    $user_c=$_POST['user_c'];
    $comment=$_POST['comment'];
    $query =  "SELECT u.id_user "
            . "FROM ".$db_assin.".utilizadores u "
            . "WHERE u.username='$user_c';";
    if($resultado = mysqli_query($link, $query)){
        if (($linha = mysqli_fetch_array($resultado, MYSQLI_ASSOC)) != NULL){
            $id_user=$linha['id_user'];
            $query =  "SELECT c.comentario "
            . "FROM ".$db_assin.".utilizadores u, ".$db_assin.".comentarios c "
            . "WHERE u.id_user=c.id_user AND u.id_user='$id_user';";
            if($resultado = mysqli_query($link, $query)){
                if (($linha = mysqli_fetch_array($resultado, MYSQLI_ASSOC)) != NULL){
                    if(strcmp($linha['comentario'],$comment)!=0){
                        if($res=ins_comment($id_user, $comment))
                                echo "Comentário submetido";
                    }
                    else{
                        echo "O mesmo comentário não pode ser submetido duas vezes!";
                    }
                }
                else{
                    if($res=ins_comment($id_user, $comment))
                        echo "Comentário submetido";
                }
            }
        }
        mysqli_free_result($resultado);
    }
    else echo mysqli_error($link);
}

Answer 1

Your second query doesn't have an order by . Try

SELECT c.comentario
FROM ".$db_assin.".utilizadores u, ".$db_assin.".comentarios c "
WHERE u.id_user=c.id_user AND u.id_user='$id_user'
ORDER BY c.id_cmnt DESC
LIMIT 1;

By the way, you should learn to use explicit join syntax. This query is better written as:

SELECT c.comentario
FROM ".$db_assin.".utilizadores u join
     ".$db_assin.".comentarios c
     on u.id_user = c.id_user
WHERE u.id_user = '$id_user'
ORDER BY c.id_cmnt DESC
LIMIT 1;

Answer 2

i tried really hard on this and i find the problem. I'm using websockets in php and jquery and in the code the mensage to websocket was writted before the post but it seems run after this. So i find for o function that send the message before the post and i discover the $.when(). Now i got this. One more time thanks for your support :)