SELECT DISTINCT(
(SELECT count(*) from books b where UPPER(b.booktitle) like UPPER("%pat%") OR UPPER(b.Authors) like UPPER("%pat%")) As  TotalCount,
x.*,
b.isbn,
b.booktitle,
b.authors,
from books b,
(select ROUND(AVG(rating),0)avg_rate,isbn from reviews group by isbn)x )
where b.isbn = x.isbn 
and UPPER(b.booktitle) like UPPER("%pat%") OR UPPER(b.Authors) like UPPER("%pat%") 

SELECT b.isbn, b.booktitle, b.authors,
       AVG (...)
FROM   books b, reviews x
WHERE  b.isbn = x.isbn 
GROUP  BY ...;