Geek Answers Handbook

How to use IF NULL, do it in MySQL?

I am trying to create a member system in which you can view specific values ​​from a database. It worked, so it’s great, but now I have a problem because I am using the NULL value for "age".

When viewing a profile page, it looks like this:

$id = $_GET["id"];

$result = mysql_query("SELECT * FROM membersfromsite WHERE `idofmember`=$_GET[id]");
$row = mysql_fetch_array($result);

echo "<b>" . $row['userusername'] . "</b>: </p>"; ?>

<?php

$id = $_GET["id"];

$result = mysql_query("SELECT * FROM membersfromsite WHERE `idofmember`=$_GET[id]");
$noage = mysql_query("SELECT ISNULL([age]) FROM membersfromsite WHERE         `idofmember`=$_GET[id]");

while ($row = mysql_fetch_array($result))
{
  echo "<p class='middle'>id-number: " . $row['idofmember'] . "<br>";
  echo "Username: " . $row['userusername'] . "<br>";
  if ($noage)
  {
    echo "Age not specified";
  }
  else
  {
    echo "Age: " .$row['age'] ;
  }
}

I tried all sorts of other things, but the problem I am facing is that it either returns "Age not specified" on each user page, or age on each user page, including pages with a NULL value, which makes it look So:

Age:

The code you see above returns the age on each page, including pages with an age that is set to NULL. I do not understand if I change the code to this:

$noage = mysql_query("SELECT * FROM membersfromsite WHERE `idofmember`=$_GET[id] AND age IS NULL");

. IS NULL = NULL, , , , IF, "while", , , ...

, , , MyQS, $noage, , - , , .

+4
3

$noage.

:

if(!$row['age'])
{
echo "Age not specified";
}
else
{
echo "Age: " .$row['age'] ;
}
+1

if($noage) if(!$row['age']) .

, , , - array('expr1' => 0), . , .

, = NULL ? , , , .

0

, MySQL, , , , PHP.

:

$id = $_GET['id'];
$result = mysql_query("SELECT * FROM membersfromsite WHERE `idofmember` = '" . mysql_real_escape_string($id) . "'");

while($row = mysql_fetch_array($result)) {
  echo '<p class='middle'>id-number: ' . $row['idofmember'] . '<br>';
  echo 'Username: ' . $row['userusername'] . '<br>';
  if($row['age'] === Null) {
    echo "Age not specified";
  } else {
    echo "Age: " .$row['age'] ;
  }
}
0

More articles:


All Articles