从数据库php爆炸/内爆

问题描述：

I'm want string out of the column data. But it failed.

enter image description here

    <?php
    $conn = mysql_connect("localhost", "nantawat", "12345678") or die(mysql_error());
    $select_db = mysql_select_db("my_db", $conn) or die(mysql_error());
    $select_tbl = mysql_query("SELECT * FROM log", $conn);

    while ($fetch = mysql_fetch_object($select_tbl)) {
        $r = $fetch->data;

    $i = explode(",", $r);

    if (!isset($i[1])) {
        for ($j = 0; $j <= 200; $j++) {
            $i[$j] = null;
        }
    }

    $name = $i[0];
    $mama = $i[1];

    $no = $i[2];
    $a = $i[3];
    $b = $i[4];

    echo $name . "</br>";
    echo $mama . $no . $a . $b . "</br>";

}

while ($data = mysql_fetch_object($select_tbl)) {

    echo $data->data . "<br>";
}

?>

enter image description here

But i want output =

bus 
car
bike
aabus
car
bike
aabus
car
bike
aabus

ddd
ee

And i not

Notice: Undefined offset: 3 in C:\xampp\htdocs\logs\New folder (2)\explode.php on line 21

Notice: Undefined offset: 4 in C:\xampp\htdocs\logs\New folder (2)\explode.php on line 22

Thank You.

答

You should just do what you want to do.

You want to connect to database then do it:

$conn = mysql_connect("localhost", "nantawat", "12345678") or die(mysql_error());

I suggest you to use mysqli library instead of mysql (mysql is deprecated in new php versions and totally removed in php7)

$conn = mysqli_connect("localhost", "nantawat", "12345678", "my_db") or die(mysql_error());

You want to query on log table, then do it:

$select_tbl = mysqli_query($conn, "SELECT * FROM log");

You want to fetch info from your result, then do it:

while ($row = mysqli_fetch_array($select_tbl)) {
    echo $row['id_user'];
    echo $row['id_doc'];
    echo $row['date'];
    echo $row['data'];
}

You want to explode data, then do it:

while ($row = mysqli_fetch_array($select_tbl)) {
    echo $row['id_user'];
    echo $row['id_doc'];
    echo $row['date'];
    $data = explode(',', $row['data']);
    foreach ($data as $d) {
        if ($d !== '') { // because before first comma or after last can be empty
            echo $d . PHP_EOL;
        }
    }
}

If you want to save database result in variables:

If you are getting only one row of database, you can save them in variables directly:

$id_user = '';
$id_doc = '';
$date = '';
$data = array();
id ($row = mysqli_fetch_array($select_tbl)) {
    $id_user = $row['id_user'];
    $id_doc = $row['id_doc'];
    $date = $row['date'];
    $tempData = explode(',', $row['data']);
    foreach ($tempData as $d) {
        if ($d !== '') {
            $data[] = $d;
        }
    }
}

And if you have multiple rows of database you need to save them all in a total array:

$array = array();
id ($row = mysqli_fetch_array($select_tbl)) {
    $id_user = $row['id_user'];
    $id_doc = $row['id_doc'];
    $date = $row['date'];
    $data = array();
    $tempData = explode(',', $row['data']);
    foreach ($tempData as $d) {
        if ($d !== '') {
            $data[] = $d;
        }
    }
    $array[] = array(
        'id_user' => $id_user,
        'id_doc' => $id_doc,
        'date' => $date,
        'data' => data,
    );
}

And finally use this to see what structure your final array has:

echo '<pre>';
pront_r($array);
echo '</pre>';

答

First off it is not wise to store comma seperated values in a single cell and you are using deprecated mysql_ functions. I think your solution can be found in using a foreach instead of the isset part:

while ($fetch = mysql_fetch_object($select_tbl)) {
    $r = $fetch->data;
    $i = explode(",", $r);
    foreach ($i as $q){
       echo $q . '<br/>';
    }
}

If you still want to access your variables $name, $mama, $no and $ab, you can use isset for those specifically.

while ($fetch = mysql_fetch_object($select_tbl)) {
    $r = $fetch->data;
    $i = explode(",", $r);
    if (isset($i[0])){
        $name = $i[0];
        echo $name . '<br>'; //only echo if it exists
    }
    if (isset($i[1])){
        $mama= $i[1];
        echo $mama. '<br>'; //only echo if it exists
   }
   //try it yourself for $no and $ab
 }

答

Try:

while ($row = mysqli_fetch_array($select_tbl)) {
    extract($row);
    /* Using extract method can get the array key value as variable  
    Below variables are available 
    $id_user;
    $id_doc;
    $date;
    $data; */
}

从数据库php爆炸/内爆

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