Generate jpa pojo in intellij ultimate 2018

#Generate jpa pojo in intellij ultimate 2018 code

Be warned, however if you return multiple columns, the returned result will be of List and it seems that there is no easy way to change that. Simply use EntityManager's createNativeQuery method. JPA2.0 added some new stuff that helps with all of these, see here.Дue to a Hibernate bug though, you cannot use TypedQuery in this case. Have many inheritance relationships in your model, which complicates your query.Need to use functions, DB features not in JPQL.This works nice, as long as it is possible to write the query in JPQL. SELECT NEW (o.rel.blah, o.rel2.blah2, o.3) FROM Object o So what we need here is some way to write a query that only extracts needed information and returns that as a POJO. The reason is, when you only need some very specific data, it is a waste to create thousands of POJOs and then use Java to extract and aggregate what's needed.

Hope you find this useful, please comment if you've found some other interesting usage!ДЄs we all know, JPA is not the greatest thing when it comes to OLAP style queries or queries that go through many relationships.

This way, you can avoid mapping the JSON column alltogether and not transmit potentially large amount of data to the client side, just to parse it in Java and read a single property. This works, but using the calculated property feature of Hibernate is more elegant: You can do this by either creating a custom JPQL query where you select the property by calling JSON_VALUE. Unfortunately there is not built-in way in JPA or Hibernate, but with a small helper class, it will work perfectly:ДЄnother interesting usage is, when you have a JSON valued column in a table, and would like to extract certain properties from it. The solution is, to inline the function parameters instead of binding them. JSON_VALUE(?, ?) ) which won't work with oracle. The reason is, that in the background, Hibernate will create a templated SQL statement (eg. Unfortunately doing the following results in an exception: This allows calling any function built into the database or defined by yourself. However, since JPA 2.0, there is a new method named CriteriaBuilder#function. This works, however is not compatible with JPA's criteria API, which means if the rest of your criteria is written using JPA, you cannot easily conjugate ('AND') it together with this restriction. If you are using Hibernate, but not JPA, one option is to use Restrictions# sqlRestriction. Unfortunately there is no easy way to do this using JPA / Hibernate.

#Generate jpa pojo in intellij ultimate 2018 code

Let's say one of your entities has a JSON property and you're writing some code to filter this table and only pick entities which has a certain JSON key with given value. Won't give you an example, this works as usual :) How can you use these functions from a JPA or Hibernate application? Here are some options.

JSON_QUERY - Return a JSON substructure.

JSON_VALUE - Return scalar value from JSON.

I've recently realized that Oracle 12 has functions that support parsing JSON strings and accessing given keys from that: