What is value field of @ColumnDefault in jpa?

user_15510171 0
Viewed 131

I am not native.

I needed to use default value in jpa.I referenced this and then I used @ColumnDefault. It works good.But I want to know role of value field of @ColumnDefault. comment of value of @ColumnDefault

The DEFAULT definition to apply to the DDL.

But I don't know what means DEFAULT definition? Even if I use @ColumnDefault("5000"), It is not applied 5000 only is applied default value 1000 of DDL.

What is role of value field of @ColumnDefault?

Thank you.

spring-data-jpa entity jpa hibernate java
1 Answers

DEFAULT definition just mean the SQL default value for a column which can be defined by following DDL:

CREATE TABLE Person (
  name VARCHAR(255) DEFAULT 'N/A'
)

The value 'N/A' is the default definition for the column name , which is equivalent to the following mapping :

@Entity(name = "Person")
public class Person {

    @Column("name")
    @ColumnDefault("'N/A'")
    private String name;

}

@ColumnDefault is only useful when you use hibernate.hbm2ddl.auto to let hibernate to auto create/update your DB schema. If you do not use such auto-schema generation feature, it will not have any effect.

user_3396370
Related