JPA: how do I persist a String into a database field, type MYSQL Text

Question

The requirement is that the user can write an article, therefore I choose type Text for the content field inside mysql database. How can I convert Java String into MySQL Text

Here you go Jim Tough

@Entity
public class Article implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private Long userId;

    private String title;

    private String content;

    private Integer vote;

    //Constructors, setters, getters, equals and hashcode
}

In my MYSQL database, content is type Text. I was hoping that there would be something like this java.sql.Text, since java.sql.Blob is an actual type, but sadly, that does not exist

Answer 1

Since you're using JPA, use the Lob annotation (and optionally the Column annotation). Here is what the JPA specification says about it:

9.1.19 Lob Annotation

A Lob annotation specifies that a persistent property or field should be persisted as a large object to a database-supported large object type. Portable applications should use the Lob annotation when mapping to a database Lob type. The Lob annotation may be used in conjunction with the Basic annotation. A Lob may be either a binary or character type. The Lob type is inferred from the type of the persistent field or property, and except for string and character-based types defaults to Blob.

So declare something like this:

@Lob 
@Column(name="CONTENT", length=512)
private String content;

References

• JPA 1.0 specification:
  • Section 9.1.19 "Lob Annotation"