Query in Spring Boot JPA - #OneToMany List relation - jpa

Question

I've got entity like this:
#Entity
#Table(name = "formula")
public class Formula {
#Id
#GeneratedValue(strategy = GenerationType.TABLE)
#Column(name = "formula_id")
private Long formulaId;
#Column(name = "name")
private String name;
#Column(name = "description")
private String description;
#Column(name = "time")
private int time;
#OneToMany(mappedBy = "formula",cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private List<Product> productList = new ArrayList<>();
And another Entity:
#Entity
#Table(name = "products")
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.TABLE)
private Long productId;
#Column(name = "product_name")
private String productName;
#Column(name = "amount")
private Double amount;
#ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinColumn(name = "formula_id")
private Formula formula;
I want to ask Query to DB which help me get every type of data (by key word). I've got all except List of <Product>. It look like this:
public interface FormulaRepository extends JpaRepository<Formula, Long> {
#Query("SELECT f FROM Formula f WHERE " + "CONCAT(f.name, f.description,
f.time)" + "LIKE %?1%")
List<Formula> findFormulaBy(String word);
How can add productList to Query and acomplished my searching? Is there any possibility to do this in findFormulaBy(String word); method?

Answer 1

Change query to include LEFT JOIN FETCH to eagerly fetch productList. Also include DISTINCT to prevent duplicate Formula objects in List
#Query("SELECT DISTINCT f FROM Formula f " +
"LEFT JOIN FETCH f.productList " +
"WHERE " + "CONCAT(f.name, f.description,f.time)" + "LIKE %?1%")
List<Formula> findFormulaBy(String word);
SQL generated by Hibernate
2022-09-10 10:16:38.287 DEBUG --- [ main] org.hibernate.SQL :
select
distinct formula0_.formula_id as formula_1_9_0_,
productlis1_.product_id as product_1_12_1_,
formula0_.description as descript2_9_0_,
formula0_.name as name3_9_0_,
formula0_.time as time4_9_0_,
productlis1_.amount as amount2_12_1_,
productlis1_.formula_id as formula_4_12_1_,
productlis1_.product_name as product_3_12_1_,
productlis1_.formula_id as formula_4_12_0__,
productlis1_.product_id as product_1_12_0__
from
formula formula0_
left outer join
products productlis1_
on formula0_.formula_id=productlis1_.formula_id
where
(
formula0_.name||formula0_.description||formula0_.time
) like ?
I see in your comment you have added f.productList list to the CONCAT function which is why you are getting a SQL error. If you want to search product fields in CONCAT function you will need to give p.productList an alias and reference the fields in this way
#Query("SELECT DISTINCT f FROM Formula f " +
"LEFT JOIN FETCH f.productList p " +
"WHERE " + "CONCAT(f.name, f.description,f.time,p.productName)" + "LIKE %?1%")
List<Formula> findFormulaBy(String word);
This seems a strange way to search formulae and products and you will be better off adding a second parameter to your SQL
#Query("SELECT DISTINCT f FROM Formula f " +
"LEFT JOIN FETCH f.productList p " +
"WHERE " + "CONCAT(f.name, f.description,f.time)" + "LIKE %?1% " +
"AND p.productName = ?2 ")
List<Formula> findFormulaBy(String word, String productName);