How to write this SQL query as a JPA query - mysql

Question

I have this query that is running successfully in mysql but I am trying to write it as a JPA query and I keep getting errors. Here are my tables.
Table 1: business_accounts{id, business_name}
Table 2: work_locations{location_id, name, contractor_id }
//contractor_id on Table2 is the foreign key matched to id on table 1.
My sql query is that I want to return all values of business_name where id from table 1 equals contractor_id from table 2 and where name="Dublin" Here is my sql query that is working in mysql:
SELECT b.business_name FROM work_locations w
inner join business_accounts b on b.id=w.contractor_id where name="Carlow"
And here is the approach that I am taking in JPA that isn't working. Any suggestions are appreciated. Thanks
String countyName="Dublin";
Query myQuery2 = em.createQuery("SELECT b FROM business_accounts b join "
+ "w where b.id=w.contractor_id and w.name=:countyName");
myQuery2.setParameter("countyName", countyName);

Answer 1

You need to create correct entities corresponding to the table.
a. Business_Account entity
b. Work_Location is the other
c. You may choose to create separate a separate join table for the join between a. and b. I would suggest that, but its your preference.
Based on the a. and b. Try something on these lines -
String countyName="Dublin";
final TypedQuery<String> query = entityManager
.createQuery(
"Select distinct b.business_name from Business_Account b, IN(b.id) location where b.id=location and location.name =:countyName", String.class); //$NON-NLS-1$
query.setParameter("countyName", countyName); //$NON-NLS-1$

Answer 2

Try the below code:
Use createNativeQuery
SELECT b.business_name instead of SELECT b
Add the ENTITY CLASS with the query that will be the return type.
String QUERY = "SELECT b.business_name FROM business_accounts b join w where b.id=w.contractor_id and w.name=?)";
List list = em.createNativeQuery(QUERY, ENTITY_CLASS_HERE.class)
.setParameter(1, countyName)
.getResultList();