在枚举列类型上休眠 @Filter

Question

This is a similar question to this: Hibernate @Filter collection of enums

But in that question it looks like the asker has an enum type of varchar on the database, which is working fine for me.

My isue is when trying to use hibernate filter annotations on entity values that have an enum column type in the database. Let's say the enum type of the column is called "database_enum"

Take entity:

@Entity
@Table(name = "table_1")
@TypeDefs(
  TypeDef(name = "enum", typeClass = PostgreSQLEnumType::class)
)
@Mockable
class table1{

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  var id: Int = 0

  ...

  @Enumerated(EnumType.STRING)
  @Type(type = "enum")
  lateinit var enumColumn: EnumClass
}

With EnumClass:

enum class EnumClass{
  TYPEA(EnumSubClass.ONE),
  TYPEB(EnumSubClass.TWO),
  ...
  TYPEN(EnumSubClass.N);

  val category: EnumSubClass

  constructor(category: EnumSubClass) {
    this.category = category
  }

  companion object {
    ...
  }
}

The filter is on a parent entity:

@Entity
@Table(name = "mla_simulation_turbine")
@FilterDefs(
  FilterDef(name = "enumTypeFilter", parameters = [ParamDef(name="enumTypeParam", type="string")])
)
@Mockable
class ParentEntity{

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  var id: Int = 0


  @OneToMany(mappedBy = "...", fetch = FetchType.LAZY)
  @Filters(
    Filter(name = "enumTypeFilter", condition="enumColumn= :enumTypeParam")
  )
  var components = mutableSetOf<EnumClass>()


}

And the filter being set like this:

val existingSession = em.unwrap(Session::class.java)
      existingSession.enableFilter("enumTypeFilter")
        .setParameter("enumTypeParam", EnumClass.TYPEA.toString())

The query in hibernate logging shows the filter as:

SELECT ...
where
        enum_column.enum_type= ? 

Finally the exception raised when I load the enum entity is an SQLGrammarException caused by:

Caused by: org.postgresql.util.PSQLException: ERROR: operator does not exist: database_enum= character varying
  Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
  Position: 925

I'm wondering if I need to refactor things and just keep the enum on the kotlin side and give it a varchar type in the database. I have not been able to find a similar post/issue with any helpful answers but here is what I have looked at:

https://forum.hibernate.org/viewtopic.php?f=1&t=1044249&view=previous

hibernate criteria filtering on a set of enum values

and a few others.

Any help or tips here would be appreciated. Thanks!

Answer 1

Ok, got the solution for anyone that could benefit from it.

You need to cast the column to text rather than cast the parameters to enum....

cast(enumColumn as text) in (:enumTypeParam)

Works like a charm.