org.postgresql.util.PSQLException：错误：列 systementi0_.id 不存在 - Hibernate、PostgreSql

Question

I'm getting error "column "systementi0_.Id does not exist". I'm using PostgreSql and Hibernate. There is code of my entity:

@Entity
@Table(name = "system_table", schema = "blue_schema")
public class SystemEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "Id", unique = true)
    private int id;

    @Column(name = "name")
    private String name;

    @Column(name = "sys_description")
    private String systemDescription;

    @Column(name = "tech_description")
    private String technologyDescritpion;

    @Column(name = "owner_name")
    private String owner;

    public SystemEntity() {
        // TODO Auto-generated constructor stub
    }

    public SystemEntity(int id, String name, String systemDescription, String technologyDescritpion, String owner) {
        super();
        this.id = id;
        this.name = name;
        this.systemDescription = systemDescription;
        this.technologyDescritpion = technologyDescritpion;
        this.owner = owner;
    }

    public SystemEntity(String name, String systemDescription, String technologyDescritpion, String owner) {
        super();
        this.name = name;
        this.systemDescription = systemDescription;
        this.technologyDescritpion = technologyDescritpion;
        this.owner = owner;
    }

At the beggining I'm trying to get every data from this table from DB.

    @Override
    public List<SystemEntity> getAllSystems() {

        Session currentSession = sessionFactory.getCurrentSession();

        Query<SystemEntity> theQuery = currentSession.createQuery("from SystemEntity", SystemEntity.class);

        List<SystemEntity> listOfSystems = theQuery.getResultList();

        return listOfSystems;
    }

That's my database types and output: Table output

Table types

My schema name is clarified in @Table annotation, but still getting error:

SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/ContractManager] threw exception [Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not extract ResultSet] with root cause
org.postgresql.util.PSQLException: Error: columnsystementi0_.id does not exist.

I saw similar post like mine but solution was simple, just add schema name in @Table.

Answer 1

maybe you should use the Integer , data type instead of int , and you should try to use the table name directly. system_table

Answer 2

It's a common mistake. The first recommendation: don't use uppercase in the name of all database entities: schemas, tables or columns. Your id column name has " Id ". Try " id ". The second: I recommend you in postresql use sequence generator:

@Entity
@Table(name = "system_table", schema = "blue_schema")
@SequenceGenerator(schema = "blue_schema", name = "system_table_seq", allocationSize = 1, sequenceName = "system_table_seq")
public class SystemEntity {

    // other code below 
    // ... 

}

And the last recommendation: don't use primitive types in JPA entities. Try to:

@Entity
@Table(name = "system_table", schema = "blue_schema")
@SequenceGenerator(schema = "blue_schema", name = "system_table_seq", allocationSize = 1, sequenceName = "system_table_seq")
public class SystemEntity {

    @Id
    @GeneratedValue(generator = "system_table_seq", strategy = GenerationType.SEQUENCE)
    private Integer id;

    // other code below 
    // ... 

}