Using Simple ORM Objects

Overview

This article goes over two ORM Objects and their uses. This is for SDK developers to work with the ORM, Decisions' feature for storing and retrieving entities in the main Decisions database. Review the SDK Overview document to learn what the Decisions SDK offers.

Typesafe vs. non-typesafe ORM accessors

Two classes represent access to ORM storage.

• ORM
• DynamicORM

The difference between these classes is the generic one adds several typesafe methods.  Below is an example of both of these.

ORM

ORM<MyCustomer> orm = new ORM<MyCustomer>();
MyCustomer mc= orm.Fetch("11223");

DynamicORM

DynamicORM orm = new DynamicORM();
IORMEntity e = orm.Fetch(typeof (MyCustomer), "11223");
MyCustomer mc = (MyCustomer) e;

Example

For the sake of this article, ORM will be used for the examples.

Fetching an object by ID

ORM<MyCustomer> orm = new ORM<MyCustomer>();
MyCustomer mc = orm.Fetch("11223");

Fetching an object with where conditions

ORM<MyCustomer> orm = new ORM<MyCustomer>();
MyCustomer[] mc = orm.Fetch(new WhereCondition[] {new FieldWhereCondition("first name", QueryMatchType.StartsWith, "J"), });

Storing an object

ORM<MyCustomer> orm = new ORM<MyCustomer>();
orm.Store(new MyCustomer() {FirstName = "Joe"});

Storing multiple objects

A list can be stored using the 'store' method on ORM.

ORM<MyCustomerAccount> orm = new ORM<MyCustomerAccount>();
orm.Store(new MyCustomer[]
{
new MyCustomer() {FirstName = "Joe"},
new MyCustomer() {FirstName = "John"}
});

A much more efficient (using batch insert mechanism in DB) is also available.

ORM<MyCustomer> orm = new ORM<MyCustomer>();
orm.BatchInsert(new MyCustomer[] 
{
new MyCustomer() {FirstName = "Joe"}
new MyCustomer() {FirstName = "John"}
});

Saving only specific fields on an object

ORM<MyCustomer> orm = new ORM<MyCustomer>();
orm.Store(new MyCustomer() {FirstName = "Joe"}, false, false, "first_name", "last_name");

The extra parameters are:

• Store relationships
• Process before and after save methods
• Fields to save

Seeing if an entity exists

ORM<MyCustomer> orm = new ORM<MyCustomer>();
if (orm.Exists("12234"))
{
   // do something
}

Getting a count of entities

ORM<MyCustomer> orm = new ORM<MyCustomer>();
long count = orm.GetCount();