解析错误：语法错误，第6行意外T_STRING

Question

I keep getting a

Parse error: syntax error, unexpected T_STRING in /newref-exec.php on line 6

I have read loads of different solutions to this problem but non seem to work

<?php
// connect to database
 require($DOCUMENT_ROOT . "connect.php");
// check for blank entries
if ($_POST[doi2] == "NULL"){
    echo "No Data to add";
    }
    else
    {
    $sql="INSERT INTO ref (uid, date, doi, title, year, journal)
    VALUES 
    ('1','CURDATE ()','$_POST[doi2]','$_POST[title2]','$_POST[year2]','$_POST[journal2]')";
    if (!mysqli_query($link,$sql,$con))
        {
        die('The Reference could not be added, beacuse of SQL Error:' . mysql_error());
        }
        echo "New Reference Added";
    }
?>

Answer 1

This line, the key needs to have quotes,

if ($_POST['doi2'] == "NULL"){

Also, if you want to check for empty entries, you need to probably do this,

if ($_POST['doi2'] == ""){ //checking "NULL", checks for a string 'NULL'

Answer 2

Rewrite the code in the below way.

<?php
// connect to database
 require($DOCUMENT_ROOT . "connect.php");
// check for blank entries
if ($_POST['doi2'] == null){
    echo "No Data to add";
} else {
        $doi2 = $_POST['doi2'];
        $title2 = $_POST['title2'];
        $year2 = $_POST['year2'];
        $journal2 = $_POST['journal2'];

        $sql="INSERT INTO ref(uid, date, doi, title, year, journal) VALUES('1', 'CURDATE()', '$doi2', '$title2', '$year2', '$journal2')";
        if (!mysqli_query($link, $sql, $con))
        {
            die('The Reference could not be added, beacuse of SQL Error:' . mysql_error());
        }
        echo "New Reference Added";
}
?>