Why the connection to MySQL but can not query, how to deal with

Why MySQL is connected and can't be queried
Form page code:

PHP Code

  
   Catalog Search
Catalog Search

PHP Code

  
Search results

  Query ($query); $num _results= $result->num_rows;echo "
Number of books found: ". $num _results."
for ($i =0; $i < $num _results; $i + +) {$row = $result->fetch_assoc (); Echo
". ($i + 1). " Title: "; Echo Htmlspecialchars (stripslashes ($row [' title ']); echo "
Author: ";    Echo stripslashes ($row [' author ']); Echo
ISBN: ";    Echo stripslashes ($row [' ISBN ']); Echo
Price: ";    Echo stripslashes ($row [' Price ']); Echo
";}? >

Output Result:

Search results
Number of books found:

Why does the query not result

------Solution--------------------
You do not check the error after executing the query, you should make up
1. Confirm that $searchtype is the correct field name
2. $query = "SELECT * from Books where". $searchtype. " Like '% '. $searchterm. " %'";
There's a space missing before the like.
Isn't it refreshing to write like this?
$query = "SELECT * from books where $searchtype like '% $searchterm% '";


------Solution--------------------
$query = "SELECT * from Books where". $searchtype. " Like '% '. $searchterm. " %'";
Echo $query, and know if it's equivalent. The Scarlet Letter part is connected, right?
------Solution--------------------
$query = "SELECT * from Books where". $searchtype. " Like '% '. $searchterm. " %'";
$query = "SELECT * from books where $searchtype like '% $searchterm% '";
There is a difference between these two SQL.
"" All of them are strings, and then you have no spaces to write directly. $searchtype .... Do you think about the results yourself?

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