I try to create ObjectScript class in Caché using dictionary(create class at runtime and compile it). Everything is ok, but when I try to add more than 857 properties to the class, it doesn't work. Error doesn't occur, but my class is not saved by clsDef.%Save().
Are here some limits to class definition? Is problem in number of properties or in size of class? Generated class should has about 9000 lines. Do someone know what causes the problem?
Thanks for ideas
(reason: It's sql mapping class for table with 1000 columns, so I need to have 1000 properties and sql storage definition for every property)
Main limits you can find in documentation. And you can see that, limit for properties is 1000 per class. Maybe you'll check other limits, and will find where you have a trouble.
Related
I'm on Enterprise Architect 14. I have a component diagram containing an interface User and two classes Employee and Customer, which both realize interface User.
Furthermore I created two instances, one of each class and specified the values of the attributes via Features & Properties > Set Run State....
Next I created a component with 2 attributes, one of type Employee and one of type Customer. Then I created an instance of the component.
Now I would like to set run state of the component instance by assigning ArbitraryUser to the Employee attribute and ArbitraryCustomer to the Customer attribute of the component instance. According documentation this should be possible (see here).
At run-time, an Object instance can have specific values for its attributes, or exist in a particular state. To model the varying behavior of Objects at run-time, use instance values selected from the 'Select ' dialog and run-time states or run-states.
However I could not figure out how to do so. Can someone help me?
AFAIK that is not possible.
I'm not sure what the quote from the help really means, but I've only ever been able to type a value for the run state.
An partial alternative would be to use associations rather than attributes to model such relations. Then you can create a link as an instance of the association to relate instances of Employee or Customer with instances of a ArbitraryComponent.
This solution doesn't work for datatypes, but it seems a bit far fetched to start modelling instances of datatypes.
I'm coming from Neo4j and evaluating OrientDB, and I had a quick question about classes - do they have to exist prior to inserting a record? That is, in Neo4j there's the 'MERGE' command, which will update or create a node if it doesn't exist. Classes seem roughly equivalent to Neo4j's labels, and if a label doesn't exist when performing a MERGE, it will be created. Is there similar functionality in OrientDB? Currently when I try to insert a record whose class doesn't exist, OrientDB throws an exception, "Class SOME_CLASS not found in database".
I've been reading through the docs trying to get a handle on the various data models available, but I can't find anything explicit on this issue. One thing I tried was to add a cluster, and then insert a record with a class that does not exist. This worked, and in OrientDB Studio, under 'DB', I see the cluster with number of records equal to '1'; however, the class of that new record does not appear under 'Schema'.
If dynamic class creation of this sort isn't possible, is it acceptable to check if a class exists in the schema, and if not, create it, and then proceed with creating the record? A different question is, if it's acceptable, is it good to do this, or should I always define the schema manually?
If you use one of the CREATE commands, then the object is placed in a default class; for example:
CREATE VERTEX
Created vertex 'V#9:0 v1' in 0.047000 sec(s).
(In this case, the class is V.)
And of course if you use the INSERT INTO ... form, then you have to specify a class.
So perhaps your first question boils down to whether it is possible to change the class of an OrientDB vertex or edge.
It is possible to change the parent class of a vertex -- see
http://orientdb.com/docs/2.1/SQL-Move-Vertex.html -- but there are important caveats.
To test whether a class exists programmatically, see e.g. this SO entry:
Check if class exists or not in orientdb
This gives a Java example, but a similar approach is possible using other supported languages.
As to the wisdom of changing the class of an entity dynamically -- perhaps the safe answer is that if you can achieve whatever you want using a property label, then use labels.
I use the Entity Framework with Db-First approach. I used to have a table called Ranking that I mapped to an abstract base class with a few inherited concrete classes. Now I recently removed all the inheritance and choose to just use one concrete class called Ranking.
But since I changed it back I get the following runtime Exception:
Type 'DbModel.Ranking' in conceptual side cannot be mapped to type 'My.Application.Models.Ranking' on the object side. Both the types must be abstract or both must be concrete types.
In my code generation I have set Abstract to false, but I don't know how to change this on the conceptual side.
I even tried deleting the Ranking table from my table designer, and then update it again from the database. This didn't help either.
Anyone an idea?
Found it. There was a partial class defined where I forgot to remove the abstract modifier.
So the generated partial class didn't had the abstract modifier anymore, but the other partial still had.
Pretty stupid after all, but hopefully this prevents some other people wasting half an hour.
Tier database and every single table has a DataSetId and I absolutely want to be sure that the data is always partitioned correctly.
Currently I'm using the QueryInterceptor attribute but it's messy and overly repetitive and prone to errors. Some new Dev could add a new table and forget to filter by DataSetId, or just rename a table. So I've put this in a base class but the IQuerable properties of my repository are never called.
I have a "CoreRepository" class that inherits from ObjectContext, and each of my IQueryable collections uses "CoreObjectSet". CoreObjectSet extends ObjectSet by always adding an expression to filter by DataSetId. When used directly this works fine. But when used for a DataService the Get accessor for the collections on the Repository are never called by the DataService. It appears to be cheating and not using them at all and accessing the data directly.
Is there a way to get the DataService to access through the repository class correctly (And still get the efficiency of passing through the query as SQL)?
If this is the behaviour why even make DataService of T anyway if it's not even going to use the class? For the ADO team to just ignore it and use the edmx directly seems like a hack.
Thanks
Aaron
Looks like the only way around it is to use a T4 template to generate the DataService. I much prefer a base class or some kind of reusable handler but ADO has given me no choice here.
What do you do with classes that have no member data, only methods?
Do you make them static?
In my case it is an repository class that executes queries against the database. Maybe I got the repository pattern wrong... (It does implement an interface)
Inherit from an Interface mean that you cannot use static. Simply create a class and instantiate it.
If it implements an interface, and gets passed around as that interface, then you can't make the members (or the class) static. The interface aspect means that although an instance won't have any actual fields, it still contains valuable information - its type.
You might want to make it a singleton, but there's no particular need to.
Why won't you make a database wrapper class, that maintains the connection to database opened/closed. Moreover, it can also open it automatically if new query is sent. You can include the functions your class has, running them right on the inner pointer to the database.
I guess this is the best database management pattern. If you use it, you should make a Factory method that returns the object of this class initialized on some specific database. Then you pass that object around.
Or if you are lazy and sure that you will need only 1 database, make it a singleton.
It depends. Most of the time it might be possible to make the class static, but sometimes you need to pass an instance of it around. Sounds like you might be having this situation. In this case perhaps you should consider a Singleton pattern, since more than 1 instance of the class is not likely to be needed?