<https://larryullman.com/forums/index.php?/topic/29-part-3-physical-products-ch8-creating-a-catalog/#comment-278>
<http://schema.org/text>
"Hi Larry, \nSeek your continued help in browse.php in Chapter8. \n  \nWhen i remove the following from browse.php: \n// If there's a problem, display the error page: \nif (!$type || !$sp_type || !$sp_cat || !$category) { \n\t$page_title = 'Error!'; \n\tinclude ('/includes/header.html'); \n\tinclude ('/views/error.html'); \n\tinclude ('/includes/footer.html'); \n\texit(); \n} \n  \nthe message in browse.php browser reads: \nAn error occurred in script 'C:\\xampp\\htdocs\\physical_product\\browse.php' on line 47: \nmysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given \n  \nline 47 in browse.php is: \nif (mysqli_num_rows($r) &gt; 0) { \n  \nThe stored procedure is well run in my win 7 computer, I have changed nothing on stored procedure and database. \n  \nWhat does the message above tell me?  What shall i do to debug it? Thank you for your time. \n  \nphp 5.3 \nmysql 5.1 \nwin 7 \ndreamweaver \n"
<https://larryullman.com/forums/index.php?/topic/29-part-3-physical-products-ch8-creating-a-catalog/#comment-308>