Spring data query where column is null

Question

Suppose I have entities (getters/setters and various details omitted for brevity):

@Entity class Customer{     ...     @OneToMany(cascade = CascadeType.ALL, mappedBy = "customer")     Collection<Coupon> coupons; }  @Entity class Coupon{     ...     @Temporal(value = TemporalType.TIMESTAMP)     private Date usedOn;      @ManyToOne(fetch = FetchType.LAZY)     @NotNull     Customer customer; } 

I wish retrieve all Coupons for a given Customer having null usedOn. I,'ve unsuccessfully defined a method in the CouponRepository as described in docs

@Repository public interface CouponRepository extends CrudRepository<Coupon, Long> {      Collection<Coupon> findByCustomerAndUsedOnIsNull(Customer); } 

but this leads on a compiler error Syntax error, insert "... VariableDeclaratorId" to complete FormalParameterList.

Answer 1

My fault, the correct definition is

@Repository public interface CouponRepository extends CrudRepository<Coupon, Long> {      Collection<Coupon> findByCustomerAndUsedOnIsNull(Customer customer); } 

I simply missed the parameter name :-(