Persist String variable to Lob with Micronaut Data JDBC

Question

I'm using Micronaut Data JDBC and I have an issue.

I have a @MappedEntity for JDBC with a content field that is a String used in a JPA context as follows:

@Lob
@Column(name = "content")
private String content;

I need to migrate this code to JDBC and I need that this content will be persisted as a Lob as well in a PostgreSQL.

With the current code, I'm just able to store the content as a String.

Any idea of how could I achieve that?

The default value for length of Colum is 255 chars. Try define `@Column(name="content" length="40000")` to exceed the capacity of a string. — saw303, Feb 08 '23 at 15:33
Thanks @saw303 but didn't work. With small strings (less than the length set) it persists the data as String, not with an ID reference like it does when using JPA and @Lob. Note: length is an int `length="40000"` — dcalap, Feb 08 '23 at 15:43

score 0 · Answer 1 · answered Feb 08 '23 at 19:50

For persisting the String content as a LOB, what needs to be done is to annotate the field as follows:

@ColumnTransformer(write = "lo_from_bytea(0, ?::bytea)")
@Column(name = "content")
private String content;

by doing this, PostgreSQL stores an ID in the content column and the data is persisted in the pg_largeobject table as it was desired.

1 Answers1