@Entity
	static class Loan {
		@Id
		@Column(name = "LOAN_ID")
		private Long id;

		@OneToMany(cascade = PERSIST, mappedBy = "exLoanId")
		private List<Extensions> extensions = new ArrayList<>();
	}

	@Entity
	static class Extensions  {
		@Id
		@Column(name = "EX_LOAN_ID")
		private Long exLoanId;
		@Id
		@Column(name = "EX_NO")
		private Long exNo;
		@Column(name = "EX_EXTENSION_DAYS")
		private Long exExtensionDays;
	}