Undefined index: learner_id

[hanspeare]

I have made this codes that registers the students using their learner id. And of course i wanted to make sure that there will be no duplication of learner id as students registered.These are my codes.

    /*
        This block is used to check whether the student_id already exists in database. 
    */
    $select_query="select student_id from student_information where learner_id = '$learner_id'";
    $result_set = mysql_query($select_query,$link_id);
 
    if($row = mysql_fetch_array($result_set)){
        $flag="exists";
        header("location:Student_login.php?flag=$flag&student_id=$student_id");
        die();
    }
    else{
        /*
            This block is used to insert the learners record in database 
            if the student_id is not yet registered in the database. 
        */
        mysql_query("SET AUTOCOMMIT = 0 ");
        if(mysql_error() != null){
            die(mysql_error());
        }    
 

Everytime there is a duplication of learner id by using this code on the other page.

>This Learner Id( <?php $_GET['learner_id'] ?> ) already exists. Please try again with another Learner Id.</td>
 

The log in page give me notice

This Learner Id(
Notice: Undefined index: learner_id in C:\xampp\htdocs\a\Student_login.php on line 61
) already exists. Please try again with another Learner Id.

How do i fix this one. Please advise.

[Bharat383]

Please check your table's learner_id collumn is set as unique or primary key then you have to set as not null.

[hanspeare]

@Bharat383

Yes already did.

[Bharat383]

would you put here your table structure.

[Rabbit]

Actually, the error is saying that your $_GET array does not have anything called learner_id.

[omerbutt]

the page where you are trrying to show the message the expression

<?php $_GET['learner_id']?>
 

the page cannot detect any set index named learner_id in the $_GET array , verify that when you land or access that page are you sending the learner_id via GET, either you are using form , or using the query string please show the complete code.
regards,
Omer Aslam