A transform to drop fields from a schema.
This transform acts as the inverse of the Select transform. A list of fields to drop
is specified, and all fields in the schema that are not specified are selected. For example:
@DefaultSchema(JavaFieldSchema.class)
public class UserEvent {
public String userId;
public String eventId;
public int eventType;
public Location location;
}
@DefaultSchema(JavaFieldSchema.class)
public class Location {
public double latitude;
public double longtitude;
}
PCollection<UserEvent> events = readUserEvents();
// Drop the location field.
PCollection<Row> noLocation = events.apply(DropFields.fields("location"));
// Drop the latitude field.
PCollection<Row> noLatitude = events.apply(DropFields.fields("location.latitude"));