I have the following query that is not working in PHP, because if you run Sql it does not present any problems.
sql= "INSERT INTO books (ISBN, Authorsname, Title, edition, year, publisher,
category, quantityinstock, price) VALUES(".$ISBN.",'".$Authorsname."',
'".$Title."', ".$edition.", ".$year.", '".$publisher."','".$category."',
".$quantityinstock.",".$price.")"
You missed the same spelling, the first without single quotes, and the second with single quotes
". $ ISBN." .... '". $ Authorsname." '
Everyone must be enclosed in single quotation marks
VALUES('".$ISBN."','".$Authorsname."', '".$Title."', '".$edition."', '".$year."', '".$publisher."','".$category."', '".$quantityinstock."','".$price."')"
or
VALUES('$ISBN','$Authorsname', '$Title', '$edition', '$year', '$publisher','$category', '$quantityinstock','$price')"
sql= "INSERT INTO 'books' ('ISBN', 'Authorsname', 'Title', 'edition', 'year', 'publisher', 'category', 'quantityinstock', 'price') VALUES('{$ISBN}','{$Authorsname}','{$Title}', '{$edition}', '{$year}', '{$publisher}','{$category}', '{$quantityinstock}','{$price}')";
If this works, there were missing single quotes in some fields .. and between {} it gets a cleaner query!