Login | Register
My pages Projects Community openCollabNet

easyobjects
Project home

On Friday, May 18, the normal maintenance window (17:00 Pacific time) will be extended for data center maintenance until 23:00 Pacific. No extended down-time is planned, but brief delays and interruptions are possible throughout the period.

If you were registered and logged in, you could join this project.

Message from the owner(s)

EasyObjects.NET is an open source ORM for managing your data layer. The architecture is based on dOOdads and the Microsoft Enterprise Library.

I highly recommend the very useful and very FREE MyGeneration to generate your EasyObjects.
Summary An ORM architecture based on the Microsoft Enterprise Library
Categories design, construction
Owner(s) mgnoonan

EasyObjects.NET

EasyObjects.NET is an object relational mapper (ORM) architecture based on a combination of the popular MyGeneration dOOdads architecture and the Microsoft Enterprise Library.

dOOdads provides a rich set of functionality for an application's business object and data layer, including support for transactions, null value handling, and standard CRUD operations.

In January, Microsoft released a major update to its popular Data Access Application Block called the Enterprise Library (EntLib). While the EntLib provides a reusable pure data layer, it lacks the rich features of a true ORM. But because it has the backing of Microsoft and their legions of developers, many companies will adopt the EntLib as their standard platform.

The goal of this project is to provide an architecture that takes advantage of all the Enterprise Library has to offer, but also offers developers the rich functionality that an ORM like dOOdads brings to the table.

Credit where credit is definitely due: EasyObjects is based largely on work done by Mike Griffin on the dOOdads architecture. In fact, they even go so far as to share some code (with permission). I want to thank Mike for his great work, and allowing this project to go forward.

Basic operations

Load all rows from a table:

Load all the rows from a given table, and iterate through the collection.

        Employees emp = new Employees();
        if (!emp.LoadAll())
        {
            string lastName;
            do
                lastName = emps.LastName;
            while(emps.MoveNext());
        }


Load one row from a table:

EasyObjects provides the user with "s_" properties that eliminate the need to check for null column values.

        Products prod = new Products();
        
        // Load a single row via the primary key
        prod.LoadByPrimaryKey(4);
        
        string productName = prod.s_ProductName;


Powerful query syntax:

One of the most popular features, the ability to query data without writing custom stored procedures.

        Employees emp = new Employees();
        
        // Limit the columns returned by the SELECT query
        emp.Query.AddResultColumn(EmployeesSchema.LastName);
        emp.Query.AddResultColumn(EmployeesSchema.FirstName);
        emp.Query.AddResultColumn(EmployeesSchema.City);
        emp.Query.AddResultColumn(EmployeesSchema.Region);
        
        // Add a WHERE clause
        emp.Where.LastName.Value = "S%";
        emp.Where.LastName.Operator = WhereParameter.Operand.Like;
        
        // Add an ORDER BY clause
        emp.Query.AddOrderBy(EmployeesSchema.LastName);
        
        //  Bring back only distinct rows
        emps.Query.Distinct = true;
        
        // Bring back the top 10 rows
        emps.Query.Top = 10;
        
        emp.Query.Load()


Built-in support for transactions:

        Products prod = new Products();
        Employees emp = new Employees();
    
        // Update the requested product
        prod.LoadByPrimaryKey(4);
        prod.UnitsInStock += 1;
    
        // Update the requested employee
        emp.LoadByPrimaryKey(1);
        emp.s_Country = "USA";
    
        // Retrieve the current transaction manager
        TransactionManager tx = TransactionManager.ThreadTransactionMgr();
    
        try
        {
            tx.BeginTransaction();
    
            // Save both objects within the same transaction
            emp.Save();
            prod.Save();
    
            // Deliberately throw an error, to cause the transaction to rollback
            throw new Exception("Deliberate exception, transaction rolled back.");
    
            tx.CommitTransaction();
        }
        catch(Exception ex)
        {
            tx.RollbackTransaction();
            TransactionManager.ThreadTransactionMgrReset();
        }

Dynamic Connections:

Another popular request (mainly because the Enterprise Library does not natively support it), EasyObjects.NET can connect to the database using parameters supplied at runtime. Developers are no longer constrained to put the connection information in dataConfiguration.config ahead of time. Of course, EasyObjects.NET can still connect by reading the configuration information from the .config file.

            Employees emps = new Employees();

            // Scenario #1 : Complete connection string, no integrated security
            emps.ConnectionString = "server=127.0.0.1;database=Northwind;User ID=sa;Password=password;Integrated Security=false;";

            // Scenario #2 : Complete connection string, with integrated security
            emps.ConnectionString = "server=127.0.0.1;database=Northwind;Integrated Security=true;";

            // Scenario #3 : Partial connection string, no login credentials
            emps.ConnectionString = "server=127.0.0.1;database=Northwind;Integrated Security=false;";
            emps.ConnectionUserID = "sa";
            emps.ConnectionPassword = "password";

            // Scenario #4 : No connection string, no integrated security, userID and password specified
            emps.ConnectionServer = "127.0.0.1";
            emps.ConnectionDatabase = "Northwind";
            emps.ConnectionUserID = "sa";
            emps.ConnectionPassword = "password";

            // Scenario #5 : No connection string, with integrated security
            emps.ConnectionServer = "127.0.0.1";
            emps.ConnectionDatabase = "Northwind";
            emps.UseIntegratedSecurity = true;


Provider independence:

Because EasyObjects are based on the Enterprise Library, you can connect to any database that is supported by the library. SQL Server and Oracle are included by default.

Dynamic query provider:

EasyObjects allows developers to substitute their own dynamic query provider through the use of the Enterprise Library Configuration Application Block. A standard query provider for SQL Server and Oracle is included by default.

Project Assumptions

  • EasyObjects, like the Enterprise Library, is written entirely in C#.
  • Dependency on other application blocks will be considered.
  • Additional data providers and dynamic query providers will be considered after version 1.0 is released.
  • The 1.0 release will not support the 2.0 .NET Framework. There is due to be an update to the EntLib which will fully support 2.0, we'll wait for that.

Related resources