php - select failed in php script with mysql_query error

Question

below is my code .I guess there is something wrong with the code in second line,but I can not figure it out PS:The db has been connected successfully !

Please help me to figure the problem out.Thanks a lot .

<?php
$today =date('Y-m-d');
$pr_result = mysql_query("SELECT mgr_open,mgr_project FROM mgr_admin WHERE mgr_start<= $today AND mgr_end >= $today")or die(mysql_error());
$pre=mysql_fetch_array($pr_result);

 
?>

Answer 1

$pr_result = mysql_query("SELECT mgr_open,mgr_project FROM mgr_admin WHERE mgr_start<= '$today' AND mgr_end >='$today'");