You haven’t provided Spring Boot with enough information to auto-configure a DataSource. To do so, you’ll need to add some properties to application.properties with the spring.datasource prefix. Take a look at DataSourceProperties to see all of the properties that you can set. You’ll need to provide the appropriate url and driver class name:
@Entity annotation defines that a class can be mapped to a table. And that is it, it is just a marker, like for example Serializable interface. And why @Entity annotation is mandatory? … well, it is the way how JPA is designed. When you create a new entity you have to do at least two … Read more
To map a composite key, you can use the EmbeddedId or the IdClass annotations. I know this question is not strictly about JPA but the rules defined by the specification also applies. So here they are: 2.1.4 Primary Keys and Entity Identity … A composite primary key must correspond to either a single persistent field or property or to a … Read more
In layman’s terms: JDBC is a standard for Database Access JPA is a standard for ORM JDBC is a standard for connecting to a DB directly and running SQL against it – e.g SELECT * FROM USERS, etc. Data sets can be returned which you can handle in your app, and you can do all … Read more
I understand that JPA 2 is a specification and Hibernate is a tool for ORM. Also, I understand that Hibernate has more features than JPA 2. But from a practical point of view, what really is the difference? I have experience using iBatis and now I’m trying to learn either Hibernate or JPA2. I picked … Read more
You are missing a field annotated with @Id. Each @Entity needs an @Id – this is the primary key in the database. If you don’t want your entity to be persisted in a separate table, but rather be a part of other entities, you can use @Embeddable instead of @Entity. If you want simply a … Read more
Your annotations look fine. Here are the things to check: make sure the annotation is javax.persistence.Entity, and not org.hibernate.annotations.Entity. The former makes the entity detectable. The latter is just an addition. if you are manually listing your entities (in persistence.xml, in hibernate.cfg.xml, or when configuring your session factory), then make sure you have also listed the ScopeTopic entity make … Read more
You should include cascade=”all” (if using xml) or cascade=CascadeType.ALL (if using annotations) on your collection mapping. This happens because you have a collection in your entity, and that collection has one or more items which are not present in the database. By specifying the above options you tell hibernate to save them to the database when saving their parent.
After <persistence-unit name=”agisdb”>, define the persistence provider name:
This is a typical bidirectional consistency problem. It is well discussed in this link as well as this link. As per the articles in the previous 2 links you need to fix your setters in both sides of the bidirectional relationship. An example setter for the One side is in this link. An example setter … Read more