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

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"

Answer 2

for mysql 'text':

@Column(columnDefinition = "TEXT")
private String description;

for mysql 'longtext':

@Lob
private String description;

Answer 3

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".