How to use PostgreSQL hstore/json with JdbcTemplate

Question

Is there a way to use PostgreSQL json/hstore with JdbcTemplate? esp query support.

for eg:

hstore:

INSERT INTO hstore_test (data) V         


        

Answer 1

Even easier than JdbcTemplate, you can use the Hibernate Types open-source project to persist HStore properties.

First, you need the Maven dependency:

    com.vladmihalcea
    hibernate-types-52
    ${hibernate-types.version}

Then, assuming you have the following Book entity:

@Entity(name = "Book")
@Table(name = "book")
@TypeDef(name = "hstore", typeClass = PostgreSQLHStoreType.class)
public static class Book {
 
    @Id
    @GeneratedValue
    private Long id;
 
    @NaturalId
    @Column(length = 15)
    private String isbn;
 
    @Type(type = "hstore")
    @Column(columnDefinition = "hstore")
    private Map properties = new HashMap<>();
 
    //Getters and setters omitted for brevity
}

Notice that we annotated the properties entity attribute with the @Type annotation and we specified the hstore type that was previously defined via @TypeDef to use the PostgreSQLHStoreType custom Hibernate Type.

Now, when storing the following Book entity:

Book book = new Book();
 
book.setIsbn("978-9730228236");
book.getProperties().put("title", "High-Performance Java Persistence");
book.getProperties().put("author", "Vlad Mihalcea");
book.getProperties().put("publisher", "Amazon");
book.getProperties().put("price", "$44.95");
 
entityManager.persist(book);

Hibernate executes the following SQL INSERT statement:

INSERT INTO book (isbn, properties, id)
VALUES (
    '978-9730228236',
    '"author"=>"Vlad Mihalcea",
     "price"=>"$44.95", "publisher"=>"Amazon",
     "title"=>"High-Performance Java Persistence"',
    1
)

And, when we fetch the Book entity, we can see that all properties are fetched properly:

Book book = entityManager
.unwrap(Session.class)
.bySimpleNaturalId(Book.class)
.load("978-9730228236");
 
assertEquals(
    "High-Performance Java Persistence",
    book.getProperties().get("title")
);

assertEquals(
    "Vlad Mihalcea",
    book.getProperties().get("author")
);