Mobile Development Basics

Question 1

How can I create 1-to-1 relationships on Entities?

Answer 1

Create the two entities, change Id type of the second Entity the the one of the first one.

Question 2

How can I enshure uniqueness of associations in many to many relationships?

Answer 2

Open the junction entities Entity Editor, go to the iondex tab. There create an index containing the two Id’s and set the index to unique. Then a db Error is raised, every time someone tries to create double relations.

Question 3

How can the performance on fetching entities be improved. What are the obstructions?

Answer 3

You can create an index on an entity attribute for which you filter the entity. Will improve the performance on large entities. Only creates indices on Id’s, for text fields they are a performance nightmare.

Question 4

How can I enshure that an action processing an aggregates data list only gets executed when the data has been fetched?

Answer 4

Use on after fetch of the Aggregate or put the action in OnReady and begin with an if which checks if the Aggregates List Boolean IsDataFetched is true.