@Entity
public class Employee {
	@Id
	private long id;
	private String firstName;
	private String lastName;
	@OneToMany(mappedBy = "parent", orphanRemoval = true, cascade = { CascadeType.ALL })
	@CascadeOnDelete
	private List<Employee> children;
	@ManyToOne
	private Employee parent;
}

CREATE TABLE EMPLOYEE (ID BIGINT NOT NULL, FIRSTNAME VARCHAR(255), LASTNAME VARCHAR(255), PARENT_ID BIGINT, PRIMARY KEY (ID))
ALTER TABLE EMPLOYEE ADD CONSTRAINT FK_EMPLOYEE_PARENT_ID FOREIGN KEY (PARENT_ID) REFERENCES EMPLOYEE (ID)

[EL Fine]: connection: 2012-09-12 11:13:21.596--Thread(Thread[main,6,main])--Detected database platform: org.eclipse.persistence.platform.database.MySQLPlatform

[EL Finest]: query: 2012-09-20 14:13:23.371--ServerSession(19334979)--Thread(Thread[main,6,main])--Execute query DataModifyQuery(sql="CREATE TABLE EMPLOYEE (ID BIGINT NOT NULL, FIRSTNAME VARCHAR(255), LASTNAME VARCHAR(255), PARENT_ID BIGINT, PRIMARY KEY (ID))")
[EL Finest]: connection: 2012-09-20 14:13:23.371--ServerSession(19334979)--Connection(24804412)--Thread(Thread[main,6,main])--Connection acquired from connection pool [default].
[EL Fine]: sql: 2012-09-20 14:13:23.371--ServerSession(19334979)--Connection(24804412)--Thread(Thread[main,6,main])--CREATE TABLE EMPLOYEE (ID BIGINT NOT NULL, FIRSTNAME VARCHAR(255), LASTNAME VARCHAR(255), PARENT_ID BIGINT, PRIMARY KEY (ID))
[EL Fine]: sql: 2012-09-20 14:13:23.371--ServerSession(19334979)--Thread(Thread[main,6,main])--SELECT 1
...
[EL Finest]: query: 2012-09-20 14:13:24.48--ServerSession(19334979)--Thread(Thread[main,6,main])--Execute query DataModifyQuery(sql="ALTER TABLE EMPLOYEE ADD CONSTRAINT FK_EMPLOYEE_PARENT_ID FOREIGN KEY (PARENT_ID) REFERENCES EMPLOYEE (ID)")
[EL Finest]: connection: 2012-09-20 14:13:24.48--ServerSession(19334979)--Connection(24804412)--Thread(Thread[main,6,main])--Connection acquired from connection pool [default].
[EL Fine]: sql: 2012-09-20 14:13:24.48--ServerSession(19334979)--Connection(24804412)--Thread(Thread[main,6,main])--ALTER TABLE EMPLOYEE ADD CONSTRAINT FK_EMPLOYEE_PARENT_ID FOREIGN KEY (PARENT_ID) REFERENCES EMPLOYEE (ID)
[EL Finest]: connection: 2012-09-20 14:13:24.652--ServerSession(19334979)--Connection(24804412)--Thread(Thread[main,6,main])--Connection released to connection pool [default].