belongs to Maven artifact androidx.room:room-common:2.0.0-alpha1

PrimaryKey

public abstract @interface PrimaryKey
implements Annotation

androidx.room.PrimaryKey


Marks a field in an Entity as the primary key.

If you would like to define a composite primary key, you should use Entity.primaryKeys() method.

Each Entity must declare a primary key unless one of its super classes declares a primary key. If both an Entity and its super class defines a PrimaryKey, the child's PrimaryKey definition will override the parent's PrimaryKey.

If PrimaryKey annotation is used on a Embeddedd field, all columns inherited from that embedded field becomes the composite primary key (including its grand children fields).

Summary

Public methods

boolean autoGenerate()

Set to true to let SQLite generate the unique id.

Inherited methods

Public methods

autoGenerate

boolean autoGenerate ()

Set to true to let SQLite generate the unique id.

When set to true, the SQLite type affinity for the field should be INTEGER.

If the field type is long or int (or its TypeConverter converts it to a long or int), Insert methods treat 0 as not-set while inserting the item.

If the field's type is Integer or Long (or its TypeConverter converts it to an Integer or a Long), Insert methods treat null as not-set while inserting the item.

Returns
boolean Whether the primary key should be auto-generated by SQLite or not. Defaults to false.