Org.Hibernate.AnnotationException: No Identifier Specified For Entity I don't have a id in my table

Question

I'm working with a table in a database and that table don't have a primary key or a proper column whith a unique value who can act as a primary key, I don't have permissions to alter that table.

What should I do? I tried putting a @id annotation in a random column and it worked, but I don't know if this is going to bring any trouble later on. what can I do?

My class

@Entity
@Table(name="my_table")
public class TheTable {
@Column (name="name", nullable=false)
    private String name;

    @Id <--- I just put this id in this random column but this column should not be a id column
    @Column (name="anyfield", nullable=false)
    private String anyfield;
}

Laniferous

You can't do anything. Hibernate needs a way to uniquely identify a row. And this unique value may not change. – Skipjack

@JBNizet In hibernate isn't there a way to implement composite keys – Symbolics

make sure you annotate 'Id' from javax.persistence package? – Amaras

Answer 1

I had this problem and was using the wrong import for @id:

Make sure it's:

import javax.persistence.Id;

and not:

import org.springframework.data.annotation.Id;

Ereshkigal

@Id needs to be an integer though, or convertible to an Integer, or am I mistaken? – Barratry

I am mistaken, my issue was elsewhere. I've managed to use an @Enumerated(EnumType.STRING) column as the id. I'm returning a single row of a single column, so this enum is unique by default. – Barratry

OP was specifically asking what to do when table has no primary key column to mark with @Id. – Acerbic

@Acerbic has noted a valid point. Even I upvoted this answer first(because this helped me fix the problem that brought me to this page), but then I read Klesun's comment and read the question again. The OP's real problem seems more like an administrative level issue than a technical issue. Solution is to talk to DB admin to identify or create a PK. I think I must vote this answer up anyway because many people will be coming here for such technical solutions. – Finite

In Java 21 I'm using import jakarta.persistence.*; – Chee

Answer 2

Hibernate is an intermediate to adress SQL databases, and since each row in a sql database should have a unique identifier, hibernate forces you to define one.

Here is an example of a generated primary key, which will be added automatically (do not forget the getter and setter)

@Id 
@GeneratedValue
@Column(name = "id")
private int id;

Since duplicates are not allowed, choosing an arbitrary column is not the way to go.

Downe

would this require an actual column called 'id'? – Uncap

This solution requires it, but if you have a column in which you only have unique values, that could be the @Id column as well. If you decide to auto-generate one, you also need that column in your database. – Downe

OK, what about where no unique value columns are being returned from a stored procedure? Could you perhaps try the following: @Id \n @GeneratedValue \n private int id; – Uncap

If you want to use hibernate and thus SQL you need to define a unique value column. The code provided automatically creates this column and fills it up. there are alternative storage systems where no primary keys are required but that is not in the scope of this question or answer. If you do not supply the @Column annotation it will create it for you. – Downe

"each row in a sql database should have a unique identifier" - this is not true. – Spiffing

Answer 3

Also had same issue. The problem was wrong import of @Id annotation. So please make sure that you not only annotate the id but also that you do it with javax.persistence.Id.

Frontality

Answer 4

JPA (not Hibernate as such) requires all entities to be uniquely identified. Sadly it doesn't allow for what you want.

JDO, on the other hand, does allow a persistable class to map to a table without PK and would handle what you need.

Lemonade

what is JDO and can you give me a link to learn it, because I don't know anything about it – Symbolics

Why not use Internet Search for "Java Data Objects" or JDO? – Lemonade

Answer 5

You can solve this using embedded id 

ex:

@Entity
@Table(name = "my_table")
public class MyTable implements Serializable {

    private static final long serialVersionUID = 1L;

    // @Id
    @Column(name = "id", insertable = false, updatable = false)
    private String id;

    @EmbeddedId
    MYtablePK pk;

    public MYtablePK getPk() {
        return pk;
    }

    public void setPk(MYtablePK pk) {
        this.pk = pk;
    }

    @Column(name = "my_table_FirstName", insertable = false, updatable = false)
    private String name;

    @Transient
    public String getName() {
        return pk.getName();
    }

    public void setName(String mrn) {
        pk.setName(name);
    }
    @Transient
        public String getSeverity() {
        return pk.getSeverity();
    }
    public void setSeverity(String severity) {
        pk.setName(name);
    }

    public String getId() {
        return pk.getId();
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return pk.getName();
    }
    public void setName(String name) {
        tpk.setName(name);
    }
}

@Embeddable
public class MyTablePK implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = -1257821517891392898L;
    @Column(name = "id")
    private String id;
    @Column(name = "name")
    private String name;
    @Column(name = "dob")
    private Date dob;
    public Date getdob() {
        return dob;
    }
    public void setdob(Date dob) {
        this.pk.setdob(dob);
    }
    @Column(name = "severity")
    private String severity;
    public String getSeverity() {
        return severity;
    }
    public void setSeverity(String severity) {
        this.severity = severity;
    }

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name

Sherbrooke

Answer 6

Its not juts Hibernate - a relational datamodel require primary keys. So what you've got is a broken data model because without a primary key it can't be relational, and this is why its difficult to use with an ORM.

for more info, here

Posthumous

Answer 7

Make sure there is p.k constraint defined for each Entity and check the import statement for Id Annotation. Check Import statement:

import javax.persistence.Id;
@Id
@Column(name="id")
@GeneratedValue 
private int id;

Knish

Answer 8

Specify a field annotated with @Id. Every @Entity requires an @Id (This is the primary key in the table). The solution for you is to use @Embeddable instead of @Entity, then you wont need to annotate any column with @Id. Change the import statement from javax.persistence.Entity; to javax.persistence.Embeddable;

Jacquez

Answer 9

Use @Embeddable annotation instead of @Entity if your class mapping is used as readOnly mapping and does not have PK or @EmbeddedKey

//@Entity
@Embeddable
@Table(name = "my_table")
public class MyTable implements Serializable {

}

Menderes

Answer 10

Basically make sure your Column annotated fields match the database table in question

Isothermal

Answer 11

requirement: table don't have a primary key or a proper column whith a unique value solution: just add a dummy column for your id, and ignore it for the rest of your select statements. imagine such a column is not there for all your requirements that doesnt need a primary key. setup some auto increment mechanism or something based on sequence, for this column. you need: permission to alter table, though, as needed.

Bagworm

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center. – Orphaorphan

Answer 12

Use @id annotation as a primary key

Footer

Answer 13

I was getting below error

for h2 database Caused by: org.hibernate.AnnotationException: No identifier specified for entity: com.codedecode.restaurantlisting.entity.Restaurant

So i missed @Id which i imported from import javax.persistence.Id;

and this resolved my issue

Hope it helps

Stelmach