PHP returns invalid MySQL resource [duplicate]

Question

    $LDATE = '#' . $_REQUEST['LDateDay'] . '/' . $_REQUEST['LDateMonth'] . '/' . $_REQUEST['LDateYear'] . '#';
    $RDATE = '#' . $_REQUEST['RDateDay'] . '/' . $_REQUEST['RDateMonth'] . '/' . $_REQUEST['RDateYear'] . '#';
    include("../../sql.php");
    $myconn2 = mysql_connect(/*removed*/, $username, $password);
    mysql_select_db(/*removed*/, $myconn2);
    $LSQLRequest = "SELECT * FROM flight WHERE DepartureDate = ".$LDATE;
    $LFlights = mysql_query($LSQLRequest, $myconn2);
    $RSQLRequest = "SELECT * FROM flight WHERE DepartureDate = ".$RDATE;
    $RFlights = mysql_query($RSQLRequest, $myconn2);

Assuming that all the $_REQUESTs are valid numerical values for their appropriate fields in the day/month/year field, how can LFlights and RFlights be invalid? When I polled the whole database I got hundreds of results so I know that the database and connection data is fine, and the field DepartureDate exists too.

Edit: When I pulled all the contents of the DB, the dates came back in the format "YYYY-MM-DD". So I converted D to a string if it was <10, then 0D. Then built a string YYYY-MM-DD. Still no results. No error now, but no results. I handpicked values that I knew had records in them.

Bill Karwin · Accepted Answer · 2010-05-03 19:14:02Z

1

MySQL only understands date literals in YYYY-MM-DD format, or a few slight variations. DD-MM-YYYY is not recognized by MySQL.

See more details at http://dev.mysql.com/doc/refman/5.1/en/datetime.html

Also as mentioned in another answer, date literals must be in single-quotes, like string literals.

If you don't include the quotes, the code you show looks like this:

SELECT * FROM flight WHERE DepartureDate = 2010/5/3.

The arithmetic expression 2010 divided by 5 divided by 3 is equal to 134.0. This is not going to match any date.

SELECT CURDATE() = 2010/5/3;

Returns false.

SELECT CURDATE() = '2010/5/3';

Returns true;

edited May 3, 2010 at 19:14

answered May 3, 2010 at 19:07

Bill Karwin

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2 Comments

Puppy Over a year ago

Single quotes was right. This answer was double right, and got both the issues. Thanks! Gonna accept as answer when the thing times out (6 minutes).

Bill Karwin Over a year ago

Thanks, I added more detail about the quotes issue so other readers will have a good explanation.

Joshua Enfield · Accepted Answer · 2010-05-03 19:04:10Z

1

Try enclosing Ldate and Rdate in the queries in single qoutes.

$LSQLRequest = "SELECT * FROM flight WHERE DepartureDate = '".$LDATE."'";
$RSQLRequest = "SELECT * FROM flight WHERE DepartureDate = '".$RDATE."'";

I also believe you do not need the # sign. That is usually an Access thing.

 $LDATE = $_REQUEST['LDateDay'] . '/' . $_REQUEST['LDateMonth'] . '/' . $_REQUEST['LDateYear'] ;
 $RDATE = $_REQUEST['RDateDay'] . '/' . $_REQUEST['RDateMonth'] . '/' . $_REQUEST['RDateYear'] ;

answered May 3, 2010 at 19:04

Joshua Enfield

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1 Comment

Puppy Over a year ago

Thanks for this. You were right. I had another issue that the below commenter also grabbed but am gonna upvote you.

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