Spring JPA – Query Methods

I have this table:

@Entity
@Table(name = "t_tropical",
        uniqueConstraints =
        @UniqueConstraint(columnNames = {
                "name",
                "sign",
                "isRetro",
                "house",
                "lang"}))
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@Builder
@ToString
public class Tropical {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String sign;
    private Boolean isRetro;
    private Integer house;
    private String lang;
    private Date updateDate;
    
}

and this method:

@Repository
public interface TropicalRepository extends JpaRepository<Tropical, Long> {

    Tropical findByHouseIsAndSignAndIsRetroAndLangIs
            (Integer house, String sign, Boolean retro, String lang);

}

but does not seems to work. I found for existing house / sign / isRetro and land and return null

>Solution :

The query approach you’ve composed within the TropicalRepository should function accurately, assuming the data in your database aligns with the stipulated conditions. Nevertheless, there’s a minor typographical error in your query method parameter name. You’ve used retro instead of isRetro. Java conventions typically employ the "is" prefix for boolean attributes, so your method should be:

Tropical findByHouseIsAndSignAndIsRetroAndLang
        (Integer house, String sign, Boolean isRetro, String lang);

Should your query still not yield the desired outcome, here are a few factors you can examine:

1. Data Correspondence: Ensure that the data within your database coincides with the criteria you’re aiming to retrieve. Verify if the values of house, sign, isRetro, and lang precisely match what you’re inputting into the query method.

2. Database Configuration: Validate that your database is properly configured and linked to your Spring Boot application.

3. Logging: Activate Spring Data JPA query logging to view the concrete SQL query being formulated and executed. You can append the following property to your application.properties or application.yml file:

   logging.level.org.springframework.data.jpa=DEBUG
   

   This will display the SQL queries in the application logs, aiding in the identification of any issues.

4. Naming Convention: Reconfirm the field names in your Tropical entity class. The letter case of the field names must match the case used in the query method. Java is case-sensitive.

5. Data Types: Ensure that the data types of the parameters in the query method correspond to the data types of the corresponding fields in the entity class.

6. NULL Values: If any of the fields (house, sign, isRetro, lang) have the potential to be null, you might need to handle this in your query method. For instance, if isRetro is null, the query won’t match any records.