使用hibernate 5如何在第一次执行时创建一个带有ROW的表？

Question

i want to insert a row in a table as with table creation time but Hibernate 5 is create table successfully but not insert my given default row like below example,

i already tried below code,

@Entity
public class FTPDomain {
@Id
private Long id=(long)1;

private String transferCroneTime="0 0 0 29 2 ?";

private String cleanCroneTime="0 0 0 29 2 ?";

//Setters & Getters
}

and i also tried ,

 @PrePersist
    public void prePersist() {
        if(id == null) id = (long)1;
        if(transferCroneTime == null) transferCroneTime ="0 0 0 29 2 ?";
        if(cleanCroneTime == null) cleanCroneTime = "0 0 0 29 2 ?"
    }

i expect when FTPDomain.java compile and execute first time create table with a ROW where id=1, transferCroneTime=0 0 0 29 2 ? and cleanCroneTime=0 0 0 29 2 ? in the table.

Thanks...

Answer 1

@PrePersist and @PreUpdate are JPA event listener, which are meant to modify entity states before the entity gets persisted or updated, as already mentioned in the comments. See the following examples for a proper usage of these event listeners.

@PrePersist
public void prePersist() {
   creationDate = Localdatetime.now();
   updatedDate = Localdatetime.now();
} 

@PreUpdate
public void preUpdate() {
   updatedDate = Localdatetime.now();
} 

If you want to pre-populate data to a freshly created schema, then you need to use the mechanisms described in this article https://thoughts-on-java.org/standardized-schema-generation-data-loading-jpa-2-1/ , whereby you configure it in your persistence.xml via the parameter javax.persistence.sql-load-script-source , which points to a sql script which loads the data via insert statements into your database.

There are also hibernate specific properties which provide the same functionality as describe in the docs https://docs.jboss.org/hibernate/orm/5.1/userguide/html_single/Hibernate_User_Guide.html#_importing_script_files , but I would recommend to use the JPA specific ones.