How to write custom findAll() with Specification in JPA repository - spring

Question

When I use skuRepository.getAll(), it works OK, but when I apply filters, defined in Specification (List filteredRegs = skuRepository.getAll(specification)) I still get all the rows of the table
What should i do to apply the specifications to my custom method?
public interface SkuRepository extends CrudRepository<Sku, Integer>, JpaSpecificationExecutor<Sku> {
#Query("select s from Sku s join fetch s.unit un join fetch s.supplier sup WHERE un.id = sku_unit_id AND sup.id = supplier_id")
List<Sku> getAll(#Nullable Specification<Sku> var1);
#Query("select s from Sku s join fetch s.unit un join fetch s.supplier sup WHERE un.id = sku_unit_id AND sup.id = supplier_id")
List<Sku> getAll();
}
UPD:
Here is my entities.
When I make sampling by a Sku table using the Specification API, I see three separate selects in log: one for Sku entity, one for Unit and one for Suppliers. I want my app to make one select with joins.
I read that this is due to the fact that I use EAGER fetch type, so I change it to LAZY, but then I got another problem: "InvalidDefinitionException: No serializer found..." This is logical because related entities Unit and Supplier are not loaded.
Then I decided to write my custom getAll() with request:
#Query("select s from Sku s join fetch s.unit un join fetch s.supplier sup WHERE un.id = sku_unit_id AND sup.id = supplier_id ORDER BY s.name")
But now it does not support Specification.
Please advise what to do.
#Entity
#Table(name = "sku")
public class Sku implements Cloneable, CloneableEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "sku_code", length = 6, nullable = false, unique = true)
private String code;
#Column(name = "sku_name", nullable = false)
private String name;
#ManyToOne(cascade = CascadeType.PERSIST, fetch = FetchType.LAZY)
#JoinColumn(name = "sku_unit_id", nullable = false)
private Unit unit;
#ManyToOne(cascade = CascadeType.PERSIST, fetch = FetchType.LAZY)
#JoinColumn(name = "supplier_id", nullable = false)
private Supplier supplier;
#Column(name = "qty_in_sec_pkg")
private int quantityInSecondaryPackaging;
#Column(name = "sku_is_active", nullable = false)
private boolean isActive;
//constructors, getters, setters
}
#Entity
#Table(name = "units")
public class Unit {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id ")
private int id;
#Column(name = "unit", nullable = false, unique = true)
private String unit;
#Column(name = "description")
private String description;
//constructors, getters, setters
}
#Entity
#Table(name = "suppliers")
public class Supplier {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id ")
private int id;
#Column(name = "supplier_code", length = 6, nullable = false, unique = true)
private String supplierCode;
#Column(name = "supplier_name", nullable = false)
private String name;
#Column(name = "create_date", length = 19, nullable = false)
private String createDate;
#Column(name = "update_date", length = 19)
private String updateDate;
//constructors, getters, setters
}

Answer 1

You can't mix #Query and Specification
You can only use JpaSpecificationExecutor interface methods to use Specification.
Find more details here