InterSystems.Data.XEP 2.4.0

InterSystems XEP

The XEP API provides support for high-speed .NET object storage and retrieval on the InterSystems IRIS data platform. It provides a high-performance object-relational mapping (ORM) persistence framework for .NET object hierarchies. XEP projects the data in .NET objects as persistent events (database objects that mirror the data structures in .NET objects) in the InterSystems IRIS database.

Getting started

Install the package

Install the IRISClient library for .NET with NuGet:

dotnet add package InterSystems.Data.XEP

The .nupkg file is also distributed with InterSystems IRIS under \<InterSystems IRIS install location\>/dev/dotnet/bin/.

Prerequisites

You need an InterSystems IRIS instance to use this package. The instance does not need to be on the same machine as the project using this package, but the project must be able to connect to the instance.

Before a persistent event can be created and stored, XEP must analyze a corresponding .NET class and import its schema into the database.

Examples

Adding a Class

Before creating the program source file, you need to create a .NET class. Your application will use this class to generate the objects for storage.

The following example uses a simple Person class:

namespace xep.demo
{
    public class Person
    {
        public string name;

        public Person() { }

        public Person(string str)
        {
            name = str;
        }
    }
}

This particular class is simple enough that XEP does not need any annotations to generate a schema. Annotations might be required for more complex classes.

Creating the XEP Program

You can now create a simple program to import the schema of the Person class, store events, and query its table:

using InterSystems.XEP;
using xep.demo;

// Generate sample data
int count = 12;
Person[] sampleArray = new Person[count];
for (int i = 0; i < count; i++)
{
    sampleArray[i] = new Person($"Name{i}");
}

string className = "xep.demo.Person";

// Connect to InterSystems IRIS and import a flat schema
EventPersister xepPersister = PersisterFactory.CreatePersister();
xepPersister.Connect("localhost", 51778, "EXTREME", "_SYSTEM", "SYS");
xepPersister.DeleteExtent(className);
xepPersister.ImportSchema(className);

// Store array of events
Event xepEvent = xepPersister.GetEvent(className);
xepEvent.Store(sampleArray);

// Query for the stored events
string sql = $"SELECT * FROM xep_demo.Person";
EventQuery<Person> xepQuery = xepEvent.CreateQuery<Person>(sql);
xepQuery.Execute();

for (int i= 0; i < count;i++)
{
    Person person = xepQuery.GetNext();
    Console.WriteLine($"Person {i} has name {person.name}");
}

// Be sure to close the query, event, and persister when finished
xepQuery.Close();
xepEvent.Close();
xepPersister.Close();

Documentation

For more information, see the InterSystems documentation and the InterSystems .NET XEP demo.