It may seem a little awkward at first, but it is type-safe. Building queries from strings isn’t, so you notice errors at runtime instead of at compile time. You can make the queries more readable by using indentations or taking each step separately, instead of writing an entire WHERE clause in a single line. To … Read more
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
It is there to specify another column as the default id column of the other table, e.g. consider the following TableA id int identity tableb_key varchar TableB id int identity key varchar unique // in class for TableA @JoinColumn(name=”tableb_key”, referencedColumnName=”key”)
If you do LIKE :code and then do namedQuery.setParameter(“code”, “%” + this.value + “%”); Then value remains free from the ‘%’ sign. If you need to use it somewhere else in the same query simply use another parameter name other than ‘code’ .
You would do that when the responsibility of creating/updating the referenced column isn’t in the current entity, but in another entity.
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