Resolution: Efficient Querying

time to read 3 min | 499 words

Well, I already covered how you can handle this challenge several times in the past, so I’ll not do that again. What I actually did is quite different. Instead of having to deal with the complexity (which is possible) I decided to remove it entirely.

The solution to my problem is to simplify the model:


Which is represented as the following physical data model:


Now, querying for this is about as simple as you can get:

select user0_.Id          as Id2_0_,
       book2_.Id          as Id0_1_,
       user0_.Name        as Name2_0_,
       user0_.Street      as Street2_0_,
       user0_.Country     as Country2_0_,
       user0_.City        as City2_0_,
       user0_.ZipCode     as ZipCode2_0_,
       user0_.HouseNumber as HouseNum7_2_0_,
       book2_.Name        as Name0_1_,
       book2_.ImageUrl    as ImageUrl0_1_,
       book2_.Image       as Image0_1_,
       book2_.Author      as Author0_1_,
       queue1_.[User]     as User1_0__,
       queue1_.Book       as Book0__,
       queue1_.[Index]    as Index3_0__
from   Users user0_
       inner join UsersWaitingBooks queue1_
         on user0_.Id = queue1_.[User]
       inner join Books book2_
         on queue1_.Book = book2_.Id
where  user0_.Id = 1 /* @p0 */

De-normalizing the model has significantly improved my ability to work with it.