Associations between Persistable and Non Persistable entity

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How many associations are there between persistable and non persistable entity in Mendix?
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4 answers
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An association between a Non-persistable and persiatable must start in the NPE.

Mendix handles the associations as follows

  1. an object of the owning entity (the entity where the association starts with a dot) contains a member storing the ID of the referenced object(s)
  2. When storing in the database a join table will store the ID's of the  referenced records. So when you do have an association between a car and a model entity, ther will be a join table IDCar-IDModel. 

Knowing this, when you have an association between a NP and NPE it must start (dot) at the NPE otherwise the owning entity is the persitable entity. which would result in a join table which stores ID's of objects which will never enter the database. Hence a non-persitable entity cannot be persisted.

 

Long story short; only association that start in a NPE can be used. A 1-1 association results in ownership at both sides and cannot be used between a NPE and PE 

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Hi,

 

Are you Start your association from non persistable entity ?

 

Regards,

Rasik.N

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I tried to give 1-1 association between persistable and non persistable entity but it throws error

as below . When to resolve error I tried to make owner as Default then the association changes to 1 – * automatically.

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HI Satyam,
There are 3 types of association in Mendix 1 – 1, 1 – *, and * – *. You can use all three between Non-persistable and persistable Entities.  But you have to make sure all the association should start from Non-Persistable to Persistable.

 

This will be different when the Same Entities are used for the Native application and the error will appear in the errors pane of your Studio pro.

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