how to retrieve values from database that are not null

Question

I'm trying to retrieve values from my table that are not null. Below is the picture of my table forumposts.

forumposts table

I want to retrieve all the thread titles that are not null. I'm using the following code :

$forum_activities = "";
$sql = "SELECT thread_title FROM forumposts WHERE thread_title IS NOT NULL";
$query = mysqli_query($db_conx, $sql);
$numrows = mysqli_num_rows($query);
if($numrows > 0)
{
    while($row = mysqli_fetch_array($query,MYSQLI_ASSOC))
    {
        $thread_titles = $row["thread_title"];
        $forum_activities .= "<a href='viewthread.php'>$thread_titles</a><hr />";
    }
}

Null values are still coming. Please help!!

It should be thread_title IS NOT NULL AND thread_title<>'' — barell
– barell, Commented Mar 23, 2014 at 13:11

underscore · Accepted Answer · 2014-03-23 13:23:35Z

2

Make your thread_title is

varchar(255) and Default value is NULL

and USe your query

CREATE TABLE IF NOT EXISTS `forumposts` (
  `thread_title` varchar(255) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;


INSERT INTO `forumposts` (`thread_title`) VALUES
('foo'),
('bar'),
(NULL);

SELECT thread_title FROM forumposts WHERE thread_title IS NOT NULL

OUTPUT

THREAD_TITLE

foo
bar

HERE IS THE WORKING SQL FIDDLE

edited Mar 23, 2014 at 13:23

answered Mar 23, 2014 at 13:15

underscore

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Xtian · Accepted Answer · 2014-03-23 13:16:01Z

1

Should be like this:

$sql = "SELECT thread_title FROM forumposts WHERE thread_title"; //Remove the IS NOT NULL
$query = mysqli_query($db_conx, $sql);
$numrows = mysqli_num_rows($query);
if($numrows > 0)
{
    while($row = mysqli_fetch_array($query,MYSQLI_ASSOC))
    {
        $thread_titles = $row["thread_title"];
        $forum_activities .= "<a href='viewthread.php'>$thread_titles</a><hr />";
    }
}

answered Mar 23, 2014 at 13:16

Xtian

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Comments

ndee · Accepted Answer · 2014-03-23 13:12:52Z

0

You can just change it into:

$sql = "SELECT thread_title FROM forumposts WHERE thread_title != ''";

Which will select anything that is different than an empty string.

answered Mar 23, 2014 at 13:12

ndee

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