A summary of Hibernate knowledge points (iv)--JPA

I. Introduction and Introduction to JPA

Jpa:java Persistence API, interface Specification
Hinernate internally provides implementations for the JPA specification
    
Development Steps (Entitymanager):
1. Import Additional packages: Hibernate-release-5.0.7.final\lib\jpa\hibernate-entitymanager-5.0.7.final.jar
2. Configure entities with JPA Annotations (entity-to-table mapping)
3. Configure the Eneitymanager core configuration file
Create a folder under the class load path (SRC), name Meta-inf
Create a core configuration file in the Meta-inf directory Persistence.xml
4. Use the Entitymanager API to manipulate entities



Two, Hibernate JPA one-to-many configuration
Create entity
Configure mapping Relationships
Customer side:
//Current customer who has contact
//One side: Config one-to-many, on the other side maintain foreign keys (a party that abandons foreign key maintenance rights)
//targetentity: Each other's bytecode object
//mappedby: Which property the other party uses to maintain the relationship with us (Mappedby is configured on the party that abandons the foreign key maintenance rights)
@OneToMany (targetentity=linkman.class,mappedby= "customer")
private Set<linkman> Linkmans = new hashset<> ();
        
Linkman Party:
//Current contact belongs to which customer
//Configure many-to-one
//targetentity: Each other's bytecode object
@ManyToOne (Targetentity=customer.class)
//Maintain foreign key joincolumn: Connection field information (foreign key information)
//name: Foreign key name referencedcolumnname: Primary key name corresponding to foreign key
@JoinColumn (name= "lkm_cust_id", Referencedcolumnname= "cust_id")
private customer customer;
        
manipulating Entities


Three, Hibernate JPA multi-to-many configuration
Create entity
Configure mapping Relationships
User side:
//What roles the user currently has
//Configure many-to-many
//targetentity: Each other's bytecode object
//mappedby: Which property the other party uses to maintain the relationship with us (the party that abandons the foreign key maintenance rights is configured)
@ManyToMany (targetentity=role.class,mappedby= "users")
private set<role> roles = new hashset<> ();
Role side:
//What users are currently using this role
//Configure many-to-many
//targetentity: Each other's bytecode object
@ManyToMany (Targetentity=user.class)
//user Discard foreign key maintenance rights role to maintain foreign keys
//configuration Relationship
//name: Name of the intermediate table
@JoinTable (
name= "Sys_user_role",
Name of//joincolumns: foreign key names generated by the party (Role) in the intermediate table
//joincolumns Referencedcolumnname: The name of the primary key corresponding to the foreign key generated by the party in the intermediate table
joincolumns={@JoinColumn (name= "rid", referencedcolumnname= "role_id")},
//inversejoincolumns Name: The other party (User) produces the foreign key names in the intermediate table
//inversejoincolumns Referencedcolumnname: The other party (User) produces the primary key name corresponding to the foreign key in the intermediate table
inversejoincolumns={@JoinColumn (name= "UID", referencedcolumnname= "user_id")}
            )
Private set<user> users = new hashset<> ();
manipulating Entities


The relationship of Orm-->jpa-->hibernate

Hibernate Knowledge Point Summary (iv)--JPA