JPA类型查询集参数

Question

I have a named parameter in JPA typed query. I am setting a list of value in condition.

I am setting a list of integer, but when JPA converts typed query to corresponding sql query it is adding a to_number function and index of the table is not used.

 List<Integer> studentIds=ArrayList<Integer>
 //Student id is number in database and indexed.     
 query = "SELECT T.* FROM STUDENT WHERE STUDENT_ID IN (:studentIds)" 
 TypedQuery<Object[]> typedQuery = entityManager().createQuery( query, Object[].class);
 typedQuery.setParameter("studentIds", studentIds);

The issue is when JPA generates the query it is adding to_number function to convert the list

SELECT * from student t4 where student_id in (?,?,?);
 filter("T4"."student_id"=TO_NUMBER(:9) OR "T4"."student_id"=TO_NUMBER(:10) OR 
  "T4"."student_id"=TO_NUMBER(:11) OR "T4"."PRODUCT_SET_ID"=student_id(:12) 

Any thoughts how to make sure JPA does not add a to_number function, so index will be used.

Answer 1

I had to use an array when I was passing values into a '.in' predicate. Try this:

List<Integer> studentIds=ArrayList<Integer>
Integer[] ids = new Integer[studentIds.size()];
ids = studentIds.toArray(ids);
//Student id is number in database and indexed.     
query = "SELECT T.* FROM STUDENT WHERE STUDENT_ID IN (:studentIds)"
TypedQuery<Object[]> typedQuery = entityManager().createQuery( query, Object[].class);
typedQuery.setParameter("studentIds", ids);