Jpa: How Do I Persist a String into a Database Field, Type Mysql Text
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...
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
3 Answers
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
Lobannotation 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 theLobannotation when mapping to a database Lob type. The Lob annotation may be used in conjunction with theBasicannotation. 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"
With @Lob I always end up with a LONGTEXTin MySQL.
To get TEXT I declare it that way (JPA 2.0):
@Column(columnDefinition = "TEXT")
private String text
Find this better, because I can directly choose which Text-Type the column will have in database.
For columnDefinition it is also good to read this.
EDIT: Please pay attention to Adam Siemions comment and check the database engine you are using, before applying columnDefinition = "TEXT".
for mysql 'text':
@Column(columnDefinition = "TEXT")
private String description;
for mysql 'longtext':
@Lob
private String description;
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
