The exception message says:
Books is not mapped [SELECT COUNT(*) FROM Books]; nested exception is org.hibernate.hql.ast.QuerySyntaxException: Books is not mapped [SELECT COUNT(*) FROM Books]
Books
is not mapped. That is, that there is no mapped type called Books
.
And indeed, there isn't. Your mapped type is called Book
. It's mapped to a table called Books
, but the type is called Book
. When you write HQL (or JPQL) queries, you use the names of the types, not the tables.
So, change your query to:
select count(*) from Book
Although I think it may need to be
select count(b) from Book b
If HQL doesn't support the *
notation.