You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax

Question

srno is being successfully fetched from a textbox

<?php
    $srno = $_POST['srno'];
    mysql_connect("localhost","root","");
    mysql_select_db("visit");
    $sql ="UPDATE visitor SET Exit='".$ab."' WHERE srno=$srno"; 
    mysql_query($sql) or die ("Error: ".mysql_error());
    ?>

you have no value for $ab is well. Which you are using in your query. $srno, is that string or number/integer?? — arif_suhail_123, Oct 06 '14 at 01:18
$ab is a date which i am able to fetch successfully and $srno is a integer — Gaurav Gupta, Oct 06 '14 at 09:56

score 4 · Answer 1 · edited May 23 '17 at 12:31

4

If $srno is a string you're missing quotes around it
$ab is not defined
Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.
You are also wide open to SQL injections

edited May 23 '17 at 12:31

Community

1
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answered Oct 06 '14 at 01:09

John Conde

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score 1 · Answer 2 · edited May 23 '17 at 11:59

To further elaborate on John (Conde's) answer, exit is a MySQL reserved word:

http://dev.mysql.com/doc/refman/5.5/en/reserved-words.html

Either rename it to something else, or wrap it in backticks:

$sql ="UPDATE visitor SET `Exit`='".$ab."' WHERE srno=$srno";
                          ^    ^ backticks

or (if $srno is a string, as John stated in his answer)

$sql ="UPDATE visitor SET `Exit`='".$ab."' WHERE srno='$srno'";

You have used mysql_error() on mysql_query() which should have signaled the syntax error, something you have not shared completely in your question, only as the question's title which does not show us the complete error message, however I am certain it is something to the effect of
...MySQL server version for the right syntax near 'Exit...

Add error reporting to the top of your file(s) which will help during production testing.

error_reporting(E_ALL);
ini_set('display_errors', 1);

which will signal an Undefined variable... warning for $ab.

Thanks Fred it was with the help of backticks that the query was able to be executed — Gaurav Gupta, Oct 06 '14 at 10:14
@GauravGupta if it work you should accept his answer. And dont forget to check the link. which he gave in his answer — arif_suhail_123, Oct 06 '14 at 10:18

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax

2 Answers2