Criteria.DISTINCT_ROOT_ENTITY不会阻止重复的对象

本文介绍了Criteria.DISTINCT_ROOT_ENTITY不会阻止重复的对象的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我有以下dao方法： @Override public List< AdminRole> findAll（）{ Session session = sessionFactory.getCurrentSession（）; Criteria criteria = session.createCriteria（AdminRole.class）; criteria.setResultTransformer（Criteria.DISTINCT_ROOT_ENTITY）; return criteria.list（）; } 其实我想从数据库中检索所有条目。 有时我会看到重复的内容。当我使用AdminRole添加用户时，会发生这种情况。 我读过使用 EAGER 获取类型这应该是修复添加以下行： criteria.setResultTransformer（Criteria.DISTINCT_ROOT_ENTITY）; 但这并不能帮助我。 $ b @Entity @Table（name =terminal_admin_role） public class AdminRole { @Id @Column（name =role_id，nullable = false，unique = true） @GeneratedValue（strategy = GenerationType.SEQUENCE，generator =user_id ） @SequenceGenerator（name =user_id，sequenceName =user_id） private长adminId; @Column（name =role）私人字符串角色; public AdminRole（String role）{ this.role = role; } public AdminRole（）{} //获得集合 @Override public String toString（）{返回角色; $ b @Override public boolean equals（Object o）{ if（this == o）{ return true; } if（！（o instanceof AdminRole））{ return false; } AdminRole adminRole =（AdminRole）o; if（！role.equals（adminRole.role））{ return false; } 返回true; @Override public int hashCode（）{ return role.hashCode（）; code @Entity @Table（name =terminal_admin） public class TerminalAdmin { @ManyToMany（fetch = FetchType.EAGER， cascade = CascadeType.ALL） @JoinTable（name =admin_role，joinColumns = { @JoinColumn（name =admin_id，nullable = false）}， inverseJoinColumns = {@JoinColumn （name =role_id， nullable = false）}） private Set< AdminRole> adminRoles; // ... } PS 我无法切换抓取类型。 我不想把这个列表放到集合中。解决方案没有理由使用 DISTINCT_ROOT_ENTITY 或类似的东西，只需要： session.createCriteria（AdminRole.class）.list（）; 如果您得到重复项，那么您确实在数据库中有它们。检查直接或通过级联从其他实体保存 AdminRole s的代码。 当级联 PERSIST / MERGE 来自其他实体的操作，请确保该操作级联到持久/分离的 AdminRole 实例，而不是瞬态（新）。 I have following dao method:@Overridepublic List<AdminRole> findAll() { Session session = sessionFactory.getCurrentSession(); Criteria criteria = session.createCriteria(AdminRole.class); criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY); return criteria.list();}Actually I want to retrieve all entries from database.Sometimes I see duplicates. This happens when I add user with AdminRole.I have read that it is possible when I use EAGER fetch type and this should be fix adding following line:criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);But this doesn't help me.my mapping:@Entity@Table(name = "terminal_admin_role")public class AdminRole { @Id @Column(name = "role_id", nullable = false, unique = true) @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_id") @SequenceGenerator(name = "user_id", sequenceName = "user_id") private Long adminId; @Column(name = "role") private String role; public AdminRole(String role) { this.role = role; } public AdminRole() { } // get set @Override public String toString(){ return role; } @Override public boolean equals(Object o) { if (this == o) { return true; } if (!(o instanceof AdminRole)) { return false; } AdminRole adminRole = (AdminRole) o; if (!role.equals(adminRole.role)) { return false; } return true; } @Override public int hashCode() { return role.hashCode(); }}and@Entity@Table(name = "terminal_admin")public class TerminalAdmin { @ManyToMany(fetch=FetchType.EAGER,cascade=CascadeType.ALL) @JoinTable(name = "admin_role", joinColumns = { @JoinColumn(name = "admin_id", nullable = false) }, inverseJoinColumns = { @JoinColumn(name = "role_id", nullable = false) }) private Set<AdminRole> adminRoles; //...}P.S.I cannot switch fetch type.I don't want to put this list into set. 解决方案 There is no reason to use DISTINCT_ROOT_ENTITY or anything similar, all you need is:session.createCriteria(AdminRole.class).list();If you get duplicates, then you really have them in the database. Check the code which saves AdminRoles either directly or by cascading from other entities.When cascading PERSIST/MERGE operations from other entities, make sure that the operation is cascaded to a persistent/detached AdminRole instance, not to a transient (new) one. 这篇关于Criteria.DISTINCT_ROOT_ENTITY不会阻止重复的对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！