CODEWITHSUNDEEP
phpmysql
Jasshh Andrews
Jasshh Andrews

Reputation: 175

Not able to view NULL values from MYsql in PHP

I have a table which contains some Role_codes Find below table

enter image description here

I'm able to get all distinct role_code from the table but in the case NULL the result is blank.

Below code for the same:

    <?php

    if ($role_code === 'BOB')
        {
        $sql = "SELECT distinct role_code FROM `create_user`";
        $result = $pdoConn->query($sql);
        if ($result !== false)
            {
            echo "<div class='w3-container w3-responsive w3-round w3-padding-
            large' style='width:95%;margin:10px;'>";
        echo " <h4 class='w3-text-indigo'>Admin please select role to view 
           record.</h4> 
<select id='view_record' name='view_record' class='w3-input w3-light-grey' style='width:90%'><option value='select Role'>Select Role</option>";
            while ($row = $result->fetch(PDO::FETCH_ASSOC))
                {
                $role_id = $row["role_code"];
                echo "<option  value=$role_id>" . $row["role_code"] . "</option>";
                }

            echo "</select></div>";
            }
        }

the above code is returning all the unique values but in the case Null it is returning blank.

Upvotes: 0

Views: 1412

Answers (3)

rowmoin
rowmoin

Reputation: 708

I think you need to check for NULL value :

if($variable === NULL) {...}

NOT

if($variable === 'NULL') {...}

Because NULL is not a string if you check NULL value as like other string value like NULL then the condition will not check for NULL value.

Upvotes: 0

e_i_pi
e_i_pi

Reputation: 4820

There's no concept of null in HTML content. When you echo null in PHP, you get an empty string. I would suggest changing your while statement to this:

while ($row = $result->fetch(PDO::FETCH_ASSOC))
{
  $role_id = $row["role_id"];
  echo "<option value='" . (is_null($role_id) ? "null" . $role_id) . "'>" . $row["role_id"] . "</option>";
}

...which then sets the value of the option to the string "null". Then, when receiving the data back on server-side after a form submission, you can convert back to null like this:

$role_id = ($_POST['view_record'] === 'null' ? null : (int)$_POST['view_record']);

Doing it this way means you preserve not only null values back and forth, but you also cater for role_id = 0, and are converting the client data from string (which is what all HTML posted variables are) to the correct database type.

Upvotes: 1

Vin
Vin

Reputation: 95

Use this in ur code

if(is_null($result['role_code']))
{
   echo "<option value='0'>Null</option>";
}else{
   echo "<option value='1'>Result...</option>";
}

and see
How to check if mysql returns null/empty
and
PHP Check for NULL

Upvotes: 1

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