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Mapping derived columns to POJOs with RecordMapper in JOOQ

i have a table tickets where i insert ticket and have a field createdBy which stores the UserId Integer of the creator of that record. During fetching I join with users table and concat firstname and last name and my DTO has field createdBy of the concatenated name of creator. How can i map the derived field? this is my reference https://www.jooq.org/doc/3.13/manual/sql-execution/fetching/pojos/ and I cant seem to find such a scenario provided
the issue is not the join. the issue is mapping the string createdBy derived after the join whereas in the record class generated by jooq is an Integer because in the database table i store the userId.
List<MyTickets> mytickets = create.select(....FIELDS).from(TICKETS_).fetch().into(MyTickets.class);
#Override
public Field<Integer> field9() {
return Tickets.TICKETS_.CREATEDBY;
}

In my answer, I will assume that your computed column is going to be called CREATED_BY_NAME, not CREATED_BY, which is a name that's already taken, and to avoid confusion.
If this is something you do frequently, you have a few options that could be interesting to you:
Use views to generate this alternative CREATED_BY_NAME column. A lot of databases can insert into / update views as well, so you won't have a big penalty in using views to replace your tables. To your client logic, the origin of this column will be transparent. If you want to work with UpdatableRecord, you will have to tell jOOQ's code generator what the view's underlying primary key is using the synthetic primary key flag.
Similar to the above views, you could use computed columns on your tables, using the GENERATED ALWAYS AS ... syntax (or whatever your dialect uses for the syntax). Not all dialects support this, but it is a nice feature that turns tables into views without the extra view object.
If you want to keep computing this column manually in your jOOQ code, you could either write your own DTO / POJO objects, or extend the code generator with a custom code section, where you generate the relevant attribute / getter / setter. This approach only works for mutable POJOs, as you cannot modify the constructor of an immutable POJO.
You can also specify a base class for all of your affected POJOs and inject that base class using a generator strategy (programmatic or configurative). The base class could then implement all the getters / setters for columns like CREATED_BY_NAME.
You can also use structural typing instead. You don't have to map all the columns into your POJO. You could also map some columns into your generated POJO (excluding CREATED_BY_NAME) and map the CREATED_BY_NAME column separately. Just keep a reference to your jOOQ Result and/or Record, and perform several map / intoXYZ() calls on it.

Hibernate, one to many from different table to general table

Good day.
Exists three tables(test):
User (id, user_name)
Object(id, object_name)
Property(id, property_value)
User, Object contain Property, so I'd like to use a special table EntityProperties(entity_id, entity_type, property_id), where entity_id - id from User or Object, and entity_type - user or object (params for tables User, Object).
May I implement it using Hibernate 4? If yes, please suggest with annotations and how better to do it.
Thanks,
Oleg

You can create a mapped super class EntityPropertyMap which has a property object and have concrete implementations(UserPropertyMap and ObjectPropertyMap) with table per class hierarchy strategy. Examples can be found http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/inheritance.html and http://viralpatel.net/blogs/hibernate-inheritence-table-per-hierarchy-mapping/

if User is also an Object then it can be done by making User extends Object and then the problem becomes mapping inheritance which you can read more about here
If this is a one way relationship from a User to Property and from Object to property then I think it can be achieved by normal mapping (one to many) and then there is no need for the entity_type column since you'll only be querying the Property table with an entity_id in hand. This way a User object will have a field Set<Property> properties; and the same for the Object class.

Map a column in Hibernate without a property in the Java class

Is it possible to map a database column using Hiberanate, so I can use it in HQL queries, but not map it to an actual property in the mapped class?
I don't need this attribute in my class and would like to avoid the clutter of getter and setter, which never should get used anyways.
The usecase I have is to set a flag on certain rows, so a different process will pick up the row and process it. We just have to do an update on the field like this:
update FJ345KJ set wrkxGrumble=1
where wrkxGrumble = 0
and -- more constraints comming here
Since the table and column names forced upon us by the database resemble hashcodes we want to use HQL for the update, which can use nice mapped names. Therefore we need the column mapped in Hibernate.

As far as I know this is not possible. Any mapped column needs a variable in the class.
What you can do is: You map the column with the attribute access = "field" and in the class you declare the variable as private. Then there still is a useless variable declared (this is not a performance issue as the database has to load the row anyway), but no getter and setter is necessary, and as the variable is declared as private it does not influence the interface of your java class, i. e. it is not visible for other classes.

Java find and compare members by string (maybe JPA feature?)

I've got alot of beans with attributes, which are derived from database tables with JPA. The users shall be able to enter any column name and a value as a string, and the app shall automatically find the correct member in the one of the beans.
I must use JPA, otherwise I would use some JDBC meta data to put all columns and values into a normal map. Is something like this possible with JPA? It only has to work from database to beans, I don't want to persist changes.
If this doesn't work, can I somehow analyze member names programmatically at runtime?

The EntityManagerFactory has a getMetamodel() method, which returns its MetaModel. From this MetaModel, you may ask for the MetaModel of every entity class, and discover all its attributes, their types, etc.

In case the JPA part doesn't work, you can access class members (fields, methods) of your class as follows:
Field[] fs = YouClass.class.getDeclaredFields();
Details for accessing different members are on this link

Hibernate: #UniqueConstraint Across Multiple Tables?

I have a data model in which a number of entities inherit some common attributes from a single superclass entity. I am using InheritanceType.JOINED on the superclass, which causes Hibernate to create a single table for attributes defined in the superclass, with subclass tables containing only columns that are added by the subclass (so to load the attributes for a subclass instance, a join is performed between the two tables). That is all working fine.
What I'd like to do, however, is specify a unique constraint that includes fields in both the subclass and superclass tables. For instance, say that my superclass entity is something like:
Thing: {id, name}
...and then I have some subclass entities like:
Company: {address} //inherits 'id' and 'name' from 'Thing'
Employee: {company} //inherits 'id' and 'name' from 'Thing'
...and I want to configure Hibernate to automatically enforce that a given Company cannot have two Employee's with the same name. The company field is in the Employee table, but the name field is in the Thing table, so is there any way to get Hibernate to enforce this constraint, or do I need to do it programmatically whenever I add a new Employee?

If it's not possible in the Database it won't be possible with Hibernate. You can't create one constraint on multiple tables with SQL so neither in Hibernate.
You could work around this by creating a new Entity holding only the company and employee id and setting a unique constraint on those 2 fields but I would recommend enforcing this programmatically.

You could not use InheritanceType.JOINED, then everything ends up in a huge table, and you could write your constraint. As said before: What you want is just not possible in a relational DB.