Is it possible for a Grails Domain to have no 'id'?

Question

Is it possible to create a table that has no \'id\'? For example, this is my domain:

class SnbrActVector {

    int nid
    String term
    double weight

    st         


        

Answer 1

Gorm requires an id field to work. You can fake an assigned id by using a transient variable like below. The getters and setters map the nid field to the id field.

When saving a domain object using this method you have to do:

snbrActVectgor.save(insert:true)

because grails thinks a non-null id is a persistent instance.

class SnbrActVector {
    Integer id
    // nid is the actual primary key
    static transients = ['nid']
    void setNid(Integer nid) {
        id = nid
    }
    Integer getNid() {
        return nid
    }

    static mapping = {
        version false
        id generator:'assigned', column:'nid', type:'integer'
    }
}

Answer 2

Yes in Oracle you can use ROWID for ID column.

class Document {
    String id

    static mapping = {
        table "DOCUMENTS"
        version false
        id column: 'ROWID'
    }

}

Answer 3

There is no way to have no "id". what you can do is change the name of "id" field using assigned id generator.

Answer 4

You probably need to specify that nid is your id column.

static mapping = {
    version false
    id generator: 'identity', column: 'nid'
}

Answer 5

Try using: "id( generator: 'assigned')" instead of "id generator: 'identity'" and see if that removes the autoincrement property from the "id" database column.