How to query server using UUIDs-CodePudding

I have a project I am working on that uses UUIDs. Unfortunately, when I try to query my DB to check if a specific UUID exists it always returns false even if I can see it in it. To check that my program works fine I switched UUIDs to normal Long IDs and all works fine. Any help would be appreciated.

This is how I generate UUIDs in my Entity:

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(insertable = false, updatable = false, nullable = false)
private UUID uuid;

This is my logic check in my service class:

boolean exists = technologyRepository.existsByUuid(t.getUuid());
if (!exists) {
    throw new IllegalStateException("Technology with id "   t.getUuid()   " does not exist." );
}

exists always returns false when using UUIDS

java.lang.IllegalStateException: Technology with id 61b78428-8bbf-4d84-997f-62e0484c21cc does not exist.

this is the UUID stored in my DB:

61b784288bbf4d84997f62e0484c21cc0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

The following is the error message I get by running the query on my H2 server directly:

Values of types "BINARY(255)" and "CHARACTER VARYING(32)" are not comparable; SQL statement: SELECT * FROM TECHNOLOGY WHERE UUID = '61b784288bbf4d84997f62e0484c21cc' [90110-214] 90110/90110

CodePudding user response：

Adding the parameter columnDefinition = 'BINARY(16) to the @Column annotation solved the issue

CodePudding user response：

in my case I used "String" for the field with UUID in the Java class mapping the table. The column in the table on the database is a VARCHAR. It has worked ok for me.

  @Entity
  @Access(AccessType.FIELD)
  @Table(name = "TABLE_WITH_UUID")
  @NoArgsConstructor
  @AllArgsConstructor
  public class TableWithUuid implements Serializable {
  private static final long serialVersionUID = 1L;
  
  [... other fields ...]
  
  @Column
  @Getter
  @Setter
  private String uuid;

  [... other fields ....]

The code to create the UUID is the following:

    UUID uuid = UUID.randomUUID();
    String uuidString = uuid.toString();

I hope it can help.