Question

我是hibernate和java的新手，我正在尝试在playframework中定义一个简单的用户 - ＆gt; groups-＆gt;权限模型，我希望在数据库级别强制执行on delete cascade规则而我不这样做希望orm关心级联（类似于python-sqlalchemy被动删除），这里是我的模型：

用户模型：

@Entity
@Table(name="auth_user")

public class User extends Model {

    @Column(name="username",nullable=false,length=40)
    @org.hibernate.annotations.Index(name = "idx_username")
    public String username;
    @Column(nullable=false,length=255)
    public String password;
    @Column(nullable=true,length=150)
    public String email;
    @Column(nullable=true,length=150)
    public String fullname;
    @Column(nullable=true)
    public boolean isAdmin;

    @OneToMany(mappedBy="group")
    public List<UserGroup> user_groups;
}

小组模特：

@Entity
@Table(name="auth_group")

public class Group extends Model {

    @Column(nullable=false,length=40)
    public String name;

    @OneToMany(mappedBy="group")
    public List<GroupPermission> group_permissions;

    @OneToMany(mappedBy="user")
    public List<UserGroup> user_groups;

许可模式：

@Entity
@Table(name="auth_permission")

public class Permission extends Model {

    @Column(nullable=false,length=40)
    public String name;
    @Column(nullable=false)
    public Integer code;

    @OneToMany(mappedBy="permission")
    public List<GroupPermission> permission_groups;

GroupPermission模型：

@Entity
@Table(name="group_permissions")

public class GroupPermission extends Model {

    @ManyToOne
    @org.hibernate.annotations.OnDelete(action=org.hibernate.annotations.OnDeleteAction.CASCADE)
    public Group group;

    @ManyToOne
    @org.hibernate.annotations.OnDelete(action=org.hibernate.annotations.OnDeleteAction.CASCADE)
    public  Permission permission;

UserGroup模型：

@Entity
@Table(name="user_groups")
public class UserGroup extends Model {

    @ManyToOne
    @org.hibernate.annotations.OnDelete(action=org.hibernate.annotations.OnDeleteAction.CASCADE)
    public User user;

    @ManyToOne
    @org.hibernate.annotations.OnDelete(action=org.hibernate.annotations.OnDeleteAction.CASCADE)
    public Group group;

这会在postgres中生成以下sql：

CREATE TABLE auth_user
(
id bigint NOT NULL,
email character varying(150),
fullname character varying(150),
isadmin boolean,
"password" character varying(255) NOT NULL,
username character varying(40) NOT NULL,
CONSTRAINT auth_user_pkey PRIMARY KEY (id)
)
WITH (
    OIDS=FALSE
);

ALTER TABLE auth_user OWNER TO postgres;
CREATE TABLE auth_group
(
id bigint NOT NULL,
"name" character varying(40) NOT NULL,
CONSTRAINT auth_group_pkey PRIMARY KEY (id)
)
WITH (
    OIDS=FALSE
);

ALTER TABLE auth_group OWNER TO postgres;

CREATE TABLE auth_permission
(id bigint NOT NULL,
 code integer NOT NULL,
 "name" character varying(40) NOT NULL,
 CONSTRAINT auth_permission_pkey PRIMARY KEY (id)
)
WITH (
    OIDS=FALSE
 );

ALTER TABLE auth_permission OWNER TO postgres;

CREATE TABLE group_permissions
(id bigint NOT NULL,
group_id bigint,
permission_id bigint,
CONSTRAINT group_permissions_pkey PRIMARY KEY (id),
CONSTRAINT fk8f9f82c43494357e FOREIGN KEY (permission_id)
    REFERENCES auth_permission (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE NO ACTION,
CONSTRAINT fk8f9f82c4c8b3dcb6 FOREIGN KEY (group_id)
    REFERENCES auth_group (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE NO ACTION
)
WITH (
  OIDS=FALSE
);

ALTER TABLE group_permissions OWNER TO postgres;

CREATE TABLE user_groups
(id bigint NOT NULL,
 group_id bigint,
 user_id bigint,
 CONSTRAINT user_groups_pkey PRIMARY KEY (id),
 CONSTRAINT fke27720c847140efe FOREIGN KEY (user_id)
    REFERENCES auth_user (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE CASCADE,
 CONSTRAINT fke27720c86e0797ca FOREIGN KEY (group_id)
    REFERENCES auth_user (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE NO ACTION,
 CONSTRAINT fke27720c8a1c053ea FOREIGN KEY (user_id)
    REFERENCES auth_group (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE NO ACTION,
 CONSTRAINT fke27720c8c8b3dcb6 FOREIGN KEY (group_id)
    REFERENCES auth_group (id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE CASCADE
 )

 WITH (
    OIDS=FALSE
 );

 ALTER TABLE user_groups OWNER TO postgres;

您可以在tabe auth_user中的用户名字段中看到索引未创建，表user_groups中的约束是重复，我有ON DELETE CASCADE和ON DELETE NO ACTION，I 只想要级联版本，在表group_permissions中未创建级联规则，

出了什么问题？

感谢尼古拉

Answer 1

你可以看到tabe auth_user中用户名字段的索引没有创建（...）

事实上。它显然应该被创建，注释部分看起来正确。作为替代方案，您可以尝试在Hibernate特定的@Table注释中定义索引。像这样：

@Entity
@org.hibernate.annotations.Table(
    name="auth_user",
    indexes = { @Index(name="idx_username", columnNames = { "username" } ) }
    )
public class User { ... }

如果这样做，这只是一种解决方法，属性级别的@org.hibernate.annotations.Index注释应该有效。

表user_groups中的约束是重复的，我有ON DELETE CASCADE和ON DELETE NO ACTION，我只想要级联版本，在表group_permissions中没有创建级联规则

不能说，不能测试，没有太多相关注释的经验。也许在Hibernate的Jira中搜索现有问题。如果找不到任何内容，请设置测试用例并创建问题。对不起，我没有更好的建议。

Answer 2

不确定，但它让我想起我遇到的一个问题。

我在第一次运行时使用“jpa.ddl = create”创建了索引（然后再切换回更新）。

在application.conf文件中：

# JPA Configuration (Hibernate)
# ~~~~~
#
# Specify the custom JPA dialect to use here (default to guess):
# jpa.dialect=org.hibernate.dialect.PostgreSQLDialect
#
# Specify the ddl generation pattern to use (default to update, set to none to disable it):
# jpa.ddl=update

# can you try this?
jpa.ddl=create

您可以尝试此配置并查看索引是否已创建？

只是我的2美分......

内部的javax.persistence / hibernate

2 个答案: