when create Index dynamically, It'll not sync the generated DefaultObjectRepository instance about nitrite-java

[anidotnet]

As far as I understand from the error message, you have not marked any field with @Id annotation in your entity class. Normally not every object needs @Id annotation but, if you do a operation like update(entity) or remove(entity) then you must add it. The id field will be used as a filter to identity the object from the repository. The other option is to use the overloaded method update(ObjectFilter filter, T update) where you need to provide a filter to identify the object.

Your code repo.createIndex(RESOURCE_ID, IndexOptions.indexOptions(IndexType.Unique)); does not mark an id field as required by Nitrite, it just creates an index.

Moreover, your example code here is not complete, the error message you mentioned OBJ_REMOVE_FAILED_AS_NO_ID_FOUND would only come from a remove(entity) operation not from update(entity) operation. If adding @Id annotation does not solve your problem, then I suggest you to add a complete reproducible code along with the entity class here, so that I can reproduce your error.

[liuhaozzu]

I know that, however, the dynamically creating index of an entity is surported by the createIndex api, I think when users invoke this API, it should have the same effect of add an @id annotation exeplicitly.

[anidotnet]

You can create as many index as you like, but those indices are not id. It is a special type of index which can only be created by using the @Id annotation. It's a design decision not to create id dynamically, otherwise it will create more problems than it will solve.

[liuhaozzu]

As I understand you create Index for id field if it's present in an entity by default. Then could we provide a default @id filed if the id is present in an entity?

[anidotnet]

I did not quite understand you, what do you mean by default id field?

To clarify, internally, nitrite converts every object to a Document and store it in a MVMap. Now Document has its own _id key which is an auto generated long field and can not be set by user and also can not be accessed by object.

The field marked with @Id annotation is just a field used as a default filter to search an object, if that is not mentioned, user need to explicitly provide search filter. This design is to keep things simple.