could not extract ResultSet
Change your query as below:
String query = "from Code where Tags='" + tags+"'";Otherwise as below:
String hql = "from Code where Tags=:tags";Query query = session.createQuery(hql);query.setParameter("tags",tags);The comparison in the where clause is with a literal and not another column. So it must be either quoted as in first case, or use a bind variable as in the second case.
Take a look at your error message (I concede that the stacktrace is long, generally the interesting part is near the top).
ERROR: ERROR: column "overloading" does not exist
from Code code0_ where code0_.Tags=Overloading
You need to quote 'Overloading', because it is not a column name, but a literal value. Even better, set it as a bind variable.
if you have camelCase then JPA will convert to Camel_Case,convert it in lowercase will be working fine.