Support multiple datasource inside dynamic attribute add-on

[glebfox]

Case:

1. Create a dynamic attribute with entity type and entity class from a secondary data store
2. Add dynamic attribute to screens
3. Try to create an entity with dynamic attribute and fill its value
4. Save

AR:

Local Exception Stack: 
Exception [EclipseLink-0] (Eclipse Persistence Services - 2.7.9.6-jmix): org.eclipse.persistence.exceptions.JPQLException
Exception Description: Problem compiling [select e from Customer e where e.id in :ids]. 
[14, 22] The abstract schema type 'Customer' is unknown.
[31, 35] The state field path 'e.id' cannot be resolved to a valid type.
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.buildException(HermesParser.java:157)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.validate(HermesParser.java:349)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.populateQueryImp(HermesParser.java:280)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.buildQuery(HermesParser.java:165)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:144)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:118)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:104)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:88)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.createQuery(EntityManagerImpl.java:1753)
    at io.jmix.eclipselink.impl.JmixEclipseLinkQuery.buildJPAQuery(JmixEclipseLinkQuery.java:557)
    at io.jmix.eclipselink.impl.JmixEclipseLinkQuery.getQuery(JmixEclipseLinkQuery.java:467)
    at io.jmix.eclipselink.impl.JmixEclipseLinkQuery.getResultList(JmixEclipseLinkQuery.java:134)

jmix-trainings-working-with-data-advanced.zip

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Jmix 2.1 test required (https://github.com/jmix-framework/jmix/issues/1721)

[gorbunkov]

Should be ported to 1.x

[KartnDev]

Won't fix.

After research, i did conclusion. There is too much changes to support entity and it's value in different datasources(databases). Right now, dynamic attribute add-on is tailored to the use of a single database. We can't place dynAttrValue entity and target entity in several databases without any hurt.

[KartnDev]

New feature that fix this: https://github.com/jmix-framework/jmix/issues/2963

[KartnDev]

Feature request:

Support working with different databases inside dynamic attribute

Current behaviour:

Right now, whole Dynamic Attribute add-on designed for single database. We need to redesign add-on so that can work with different databases. E.g.

Entity -> Primary DB DynamicAttributeValue (entity) -> Secondary DB DynamicAttributeValue.value (for example Entity has dynamic field that entity field too) -> Tertiary DB

And that should works

[KartnDev]

UPD: Current behaviour

1. Entity link won't work when reference refers to the entity which located in other datasource.
2. If "Dynamic attributed" entity located "not primary database" and it's attribute refers to the primary datasource entity - all fine and works.

Conclusions

1. Dynamic attributes still working with any of entity that located in any of datasource
2. If you want to refer the entity dynamically, you need to sure that CategoryAttributeValue entity located in same datasource neither do your target dynamic "Referred" entity.