Accessing Database Instances

The JoobContext class provides methods to access database objects from a specified class.

Method	Returns …
FirstInstance<T>	The first instance of a class
FindInstance<T>	An object with the specified OID
LastInstance<T>	The last instance of a class
AllInstances<T>	All instances of a class

The following typical sequence of C# calls returns the first instance of the Company class, iterates through a collection on the class, and uses references and methods of the objects in the collection.

JoobContext context = new JoobContext();
Company company = context.FirstInstance<Company>();

If you know the object identifier (OID) of a JADE database object, you can obtain a reference to that object in your C# code, as shown in the following example.

JoobContext context = new JoobContext();
ObjectId oid = new ObjectId(3272, 1);
Agent comp = context.FindInstance<Agent>(oid);

In the following example, a virtual collection of instances of the Stock class is iterated.

JoobContext context = new JoobContext();
foreach (Agent agent in context.AllInstances<>(Agent))
{
    // process agent
}