PHP - 在多维数组中存储mysql_fetch_assoc

Question

I'm new to PHP, so I'm not exactly sure how it works.

Anyway, I would line to return a multidimensional array to another method, essentially something storing a small amount of record and columns, table like structure.

I've written the following, no warning but no data either

public function GetData($sqlquery)
{
    include 'config.php';

    $result = mysql_query($sqlquery,$con);
    $data = array();

    while($row = mysql_fetch_assoc($result))
    {
        $data[] = $row;
    }

    return $data;
}

Most likely doing something stupid

Help appreciated.

EDIT:

Thanks for all the fast replies

I figured out why this wasn't working, I was addressing the array as such

print $data[0][0];

Rather than

print $data[0]['title']; 

for example, thanks all :)

PS I really find it hard to believe you can't say $data[0][5], It's more logical IMO than specifying a string value for location

Answer 1

Your code seems okay. At least, you're going in right direction.

Just some minor corrections:

• NEVER include config inside of a function. it should be done in class constructor
• if you really want to use connection identifier - make it class variable. But for most applications using single connection to db its unnecessary to use $con, so you can omit it
• error handling is absolutely necessary

so,

public function GetData($sqlquery)
{
    $data = array();
    $result = mysql_query($sqlquery) or trigger_error(mysql_error().$sqlquery);
    if ($result)
    {
        while($row = mysql_fetch_assoc($result))
        {
            $data[] = $row;
        }
    }
    return $data;
}

run this code and see what it says.

Answer 2

If you used the mysqli extension instead of mysql you could use fetch_all() which is faster than filling the array in a loop. So your function only needs to return the result of fetch_all()

return $result->fetch_all(MYSQLI_ASSOC);

Script

<?php

ob_start(); 

try
{
    $db = new mysqli("localhost", "foo_dbo", "pass", "foo_db", 3306);

    if ($db->connect_errno) 
        throw new exception(sprintf("Could not connect: %s", $db->connect_error));

    $sqlCmd = "select * from users order by username";

    $startTime = microtime(true);

    $result = $db->query($sqlCmd);

    if(!$result) throw new exception(sprintf("Invalid query : %s", $sqlCmd));

    if($result->num_rows <= 0){
        echo "no users found !";
    }
    else{

        $users = $result->fetch_all(MYSQLI_ASSOC); //faster 

        //while($row = $result->fetch_assoc()) $users[] = $row; //slower

        echo sprintf("%d users fetched in %s secs<br/>", 
            count($users), number_format(microtime(true) - $startTime, 6, ".", ""));

        foreach($users as $u) echo $u["username"], "<br/>";
    }
    // $result->close();
}
catch(exception $ex)
{
    ob_clean(); 
    echo sprintf("zomg borked - %s", $ex->getMessage());
}
//finally
if(!$db->connect_errno) $db->close();
ob_end_flush();
?>

Testing

//fetch_all()

 1000 users fetched in 0.001462 secs
 5000 users fetched in 0.005493 secs
15000 users fetched in 0.015517 secs
50000 users fetched in 0.051950 secs
100000 users fetched in 0.103647 secs

//fetch_assoc plus loop

 1000 users fetched in 0.001945 secs
 5000 users fetched in 0.008101 secs
15000 users fetched in 0.023481 secs
50000 users fetched in 0.081441 secs
100000 users fetched in 0.163282 secs

Answer 3

Maybe I'm wrong, if all this happens in config.php , but I think, yu miss a few steps:

Create connection:

$con = mysql_connect("localhost", "mysql_user", "mysql_password");

Select database:

mysql_select_db("mydbname");

After this, comes the mysql_query . But you say there are no warnings, so I assume, you do all this.

I would do something like this (there are better, more complex solutions):

include 'config.php'; // contains definition of $conf array

$con = mysql_connect($conf['host'], $conf['user'], $conf['pass']);
mysql_select_db($conf['db']);

function GetData($sqlquery)
{
    global $con;

    $result = mysql_query($sqlquery,$con);
    $data = array();

    while($row = mysql_fetch_assoc($result))
    {
        $data[] = $row;
    }

    return $data;
}