How can solve JSON column in H2

Question

I use in application MySQL 5.7 and I have JSON columns. When I try running my integration tests don\'t work because the H2 database can\'t create the table. This is the erro

Answer 1

Example with Kotlin + Spring + Hibernate + Postgres + jsonb column

Create the entity:

@Entity
@TypeDef(name = "jsonb", typeClass = JsonBinaryType::class)
class MyEntity(
    @Type(type = "jsonb")
    @Column(columnDefinition = "jsonb")
    val myConfig: String,

    @Id
    @GeneratedValue
    val id: Long = 0,
)

JsonBinaryType.class comes from https://github.com/vladmihalcea/hibernate-types

    com.vladmihalcea
    hibernate-types-52
    2.9.13

Configure your H2 database in spring profile. The key line is this: INIT=create domain if not exists jsonb as other

spring:
    profiles: h2

    datasource:
        driver-class-name: org.h2.Driver
        url: jdbc:h2:mem:testdb;INIT=create domain if not exists jsonb as other;MODE=PostgreSQL;DB_CLOSE_DELAY=-1
        username: sa
        password: sa

spring.jpa.hibernate.ddl-auto: create

Write the test:

// Postgres test
@SpringBootTest
class ExampleJsonbPostgres(@Autowired private val myEntityRepository: MyEntityRepository) {
    @Test
    fun `verify we can write and read jsonb`() {
        val r = myEntityRepository.save(MyEntity("""{"hello": "world"}"""))
        assertThat(myEntityRepository.findById(r.id).get().config).isEqualTo("""{"hello": "world"}""")
    }
}

// H2 test
@ActiveProfiles("h2")
@SpringBootTest
class ExampleJsonbH2(@Autowired private val myEntityRepository: MyEntityRepository) {
    @Test
    fun `verify we can write and read jsonb`() {
        val r = myEntityRepository.save(MyEntity("""{"hello": "world"}"""))
        assertThat(myEntityRepository.findById(r.id).get().config).isEqualTo("""{"hello": "world"}""")
    }
}

Alternatively you can try to define custom type per database in hibernate XML as described here: https://stackoverflow.com/a/59753980/10714479