Set fields null from POJO using JOOQ - jooq

Question

According to this entry from the JOOQ blog, the section titled "SQL DEFAULT expressions and POJOs" indicates that any null fields from a POJO will set the column to null, since every Record.changed() flag will be set to true.
In practice, I have not found this to be the case-- if a POJO field is null and I follow the example in the blog, existing values are retained. I want to set these fields to null, but how can I do it using POJOs?
// Load the customer record from a POJO
CustomerRecord customer = ctx.newRecord(CUSTOMER, customerPojo);
customer.update();
// Expected behavior: null fields in customerPojo will set db values to null
// Actual behavior: null fields in customerPojo do not change values in db
Edit: This is using Jooq 3.11.10, Postgres 10.6.
Create customer script:
drop table if exists customers;
create table customers
(
id serial not null primary key,
first_name text,
last_name text
);
Customer Class:
#Data
#Builder(toBuilder = true)
#NoArgsConstructor
#AllArgsConstructor
public class Customer {
private Integer id;
private String firstName;
private String lastName;
public static Customers TAB = Customers.CUSTOMERS;
static DSLContext ctx = PostgresSingleton.getMainCtx();
public Customer store(){
CustomersRecord rec = ctx.newRecord(TAB, this);
if(getId() == null) {
rec.store();
}
else {
rec.update();
}
rec.refresh();
return rec.into(Customer.class);
}
}
Test (Spock/Groovy):
def "Customer test"() {
when: "save a new customer"
Customer cust = Customer.builder().firstName("Phil").lastName("H").build().store()
then: "ID populated"
def custId = cust.getId()
custId != null
when: "null out last name"
cust.toBuilder().lastName(null).build().store()
then: "last name actually set to null"
cust.getId() == custId
cust.getFirstName() == "Phil"
cust.getLastName() == null //fails, still is "H"
}
Edit 2:
It appears the .update() call is in fact nulling the field in the DB! However, the .into() call afterwards does not refresh the POJO with the null field as expected. I verified the value for lastName is null after .refresh(), but the into() call doesn't null the value.

Answer 1

Well, it was a PEBKAC error-- I wasn't storing the result of my update back into the same object in my test:
when: "null out last name"
cust.toBuilder().lastName(null).build().store() //not storing the result!
should be:
when: "null out last name"
cust = cust.toBuilder().lastName(null).build().store()
Easy to miss.