Dialect means “the variant of a language”. Hibernate, as we know, is database agnostic. It can work with different databases. However, databases have proprietary extensions/native SQL variations, and set/sub-set of SQL standard implementations. Therefore at some point hibernate has to use database specific SQL. Hibernate uses “dialect” configuration to know which database you are using … Read more
You would do that when the responsibility of creating/updating the referenced column isn’t in the current entity, but in another entity.
You could handle this by creating a custom MessageBodyReader. The example below is based on a Customer model: import java.io.IOException; import java.io.InputStream; import java.lang.annotation.Annotation; import java.lang.reflect.Type; import java.net.URL; import javax.ws.rs.Consumes; import javax.ws.rs.WebApplicationException; import javax.ws.rs.core.Context; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.MultivaluedMap; import javax.ws.rs.ext.ContextResolver; import javax.ws.rs.ext.MessageBodyReader; import javax.ws.rs.ext.Provider; import javax.ws.rs.ext.Providers; import javax.xml.XMLConstants; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Unmarshaller; import … Read more
Read this very nice article on the subject: Don’t Let Hibernate Steal Your Identity. The conclusion of the article goes like this: Object identity is deceptively hard to implement correctly when objects are persisted to a database. However, the problems stem entirely from allowing objects to exist without an id before they are saved. We … Read more