休眠在插入之前删除所有行

我有一个实体类,是我为测试Hibernate构建的第一个实体类,它使用oracle序列填充ID字段:

@Entity
@Table(name="COMPANIES")
public class Companies {

                private Integer cmpid;
                private String cmpname;
                private String cmpcountry;

                public Companies() {

                }

                public Companies(String name, String country) {
                    this.cmpname = name;
                    this.cmpcountry = country;
                }
                    @Id
                    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "gen_CMP")
                    @SequenceGenerator(name="gen_CMP", sequenceName = "CMP_ID_SEQ")
                    @Column(name="CMP_ID", nullable=false)
                    public Integer getCmpId() {
                    return this.cmpid;
                    }

                    public void setCmpId(Integer cmpid) {
                    this.cmpid = cmpid;
                    }

                    @Column(name="CMP_NAME", nullable=true)
                    public String getCmpName() {
                    return this.cmpname;
                    }

                    public void setCmpName(String cmpname) {
                    this.cmpname = cmpname;
                    }

                    @Column(name="CMP_COUNTRY", nullable=true)
                    public String getCmpCountry() {
                    return this.cmpcountry;
                    }

                    public void setCmpCountry(String cmpcountry) {
                    this.cmpcountry = cmpcountry;
                    }

}

然后在我的测试单元中,创建一个Companies对象,然后将其保存在会话中:

Companies Companies = new Companies("qqq","FR");
session.save(Companies);
transaction.commit();

但每次,它都会删除Oracle中COMPANIES表中的所有记录。

所以我第一次尝试我的数据时,它充满了许多行,并且在其他表中使用了这个主键,它能够删除公司中的那些行,而不是其他表。。。

我做错什么了?

我不想hibernate弄乱我的数据,除非我告诉它这样做。。。