Building Informix Data- Driven Applications with.Net Sean R. Durity Manager of IT CornerCap Investment Counsel Informix User Forum 2006 Washington, D.C. December 8-9, 2006

Agenda The IBM Informix ADO.Net Driver ADO.Net Driver Basics (with examples) Building A Real Application (demo) Q & A

The Informix ADO.Net Driver Current version is Client SDK 2.90TC6 Now installed by default, must have.Net framework 1 st (works with either 1.1 or 2.0 framework) Namespace is IBM.Data.Informix - reference the library IBM.Data.Informix.dll Client SDK must be installed on any client that will use the driver (not self-contained in the.dll) Current documentation and examples are better than the previous ones; reference guide twice as long Objects are similar to Microsoft’s Sql* objects, but use “Ifx” prefix (IfxConnection, IfxCommand, etc.)

The Informix ADO.Net Driver Installation Issues –If you have the older driver (2.81), you should either install into the same directory or remove the previous installation first. I could not get the two versions to peacefully co-exist. –There is a stored procedure creation script that must be run once against the sysmaster database (as user ‘informix’). Otherwise, features like the DataAdapter wizard won’t connect. Script is $INFORMIXDIR/etc/cdotnet.sql on any client machine.

The Informix ADO.Net Driver New features in 2.90 –Adds an IfxDataAdapter Configure Data Adapter wizard –Adds new types including IfxDateTime, IfxDecimal, IfxBlob, and IfxClob –Supports IPv6 protocol

The Informix ADO.Net Driver Basics Connection String (getting a connection) –Semi-colon delimited list of attributes put into the ConnectionString property of the IfxConnection object string ConnectionString = "Host=" + HOST + "; " + "Service=" + SERVICENUM + "; " + "Server=" + SERVER + "; " + "Database=" + DATABASE + "; " + "User Id=" + USER + "; " + "Password=" + PASSWORD + "; "; IfxConnection conn = new IfxConnection(); conn.ConnectionString = ConnectionString; try { conn.Open(); } catch (IfxException ex) { }

The Informix ADO.Net Driver Basics Executing an insert, update or delete IfxCommand cmd = new IfxCommand("insert into test values (1, 2, ‘ABC’)",bconn.conn); cmd.CommandTimeout = 200; //seconds allowed for command to finish, default is 30 try { int rows = cmd.ExecuteNonQuery(); } catch (IfxException ex) { Console.WriteLine("Error "+ex.Message); }

The Informix ADO.Net Driver Basics Iterating through a SELECT’s result set one-time IfxCommand cmd = new IfxCommand("select * from test",bconn.conn); try { IfxDataReader dr = cmd.ExecuteReader(); while (dr.Read()) { int a = dr.GetInt32(0); int b = Convert.ToInt32(dr["b"]); string c = (String)dr[2]; } dr.Close(); } catch (IfxException ex) { Console.WriteLine("Error "+ex.Message); }

The Informix ADO.Net Driver Basics Executing a Stored Procedure with “in” parameter IfxCommand cmd = new IfxCommand("test_proc",bconn.conn); cmd.CommandType = CommandType.StoredProcedure; //from System.Data cmd.Parameters.Add("in_parameter",2); //many ways to create these try { cmd.ExecuteScalar(); } catch (IfxException ifxe) { Console.WriteLine("Error "+ifxe.Message); }

ADO.Net 2.0 MicroSoft fixed some underlying problems with its DataSet implementation (indexing). For large DataSets it can provide an order of magnitude performance improvement. –Note: the current Informix driver has its own performance problems marshaling data from unmanaged to managed code. This also impacts the performance of large DataSets. Driver Availability from IBM – Open Beta just announced on (12/02/2006)

Building Data Applications The DataSet –Microsoft’s disconnected database object – like an in-memory database –One or more DataTables Each DataTable has a DataAdapter that interacts with the actual data store –Can have primary keys, relations, etc. –Derived from ComponentModel, so it is available in the Designer as graphical object

DataSet Diagram

Framework Considerations Concurrency checking –Could be implemented with interface and concurrency column Data binding – built-in can be flaky and not always bi- directional Data caching and lazy instantiation Can’t make DataSets “global” and still use designer- aided binding How to define relations between objects Null field checking; null objects allowed? How to send data across the wire in n-tier architecture Open source.Net ORM frameworks (like nHibernate) still emerging – no Informix-specific implementations that I have found

DevForce Framework from IdeaBlade

DevForce Editions Express – Free version: ORM, UI DataBinding, RAD features, one-click deployment, royalty free Professional – support for stored procedures, databinding to 3 rd party controls, multiple database connections, support Enterprise – Business Objects Server for n-tier deployment, disconnected or offline functionality, distributed transactions, web services objects (at CornerCap, we use this one)

DevForce Framework Particulars Uses OleDb for ORM (must run coledb script against sysmaster) No direct support for serial datatype, but I have Informix id generator code I am willing to share Includes its own object query language for writing queries (will probably move to LINQ. Pass-thru sql allowed.) Uses.Net Remoting for moving objects between tiers Concepts Guide is a must-read; other documentation, videos, and samples are good

DevForce – How Does it Work? ORM tool generates a DataRow class for each table/object (e.g., PlayerDataRow) Generates a descendent class from the DataRow (Player). This is where your custom code goes PersistenceManager class handles interactions with the database (no data adapters) BindingManagers handle UI binding Business objects have relationships that allow for “dot navigation” of properties from related objects Let’s go to the demo!

Q&A/Discussion Other Resources –DevForce framework ( especially read the Concepts Guide! –DevForce user group ( –Expert C# 2005 Business Objects, 2 nd ed. Rockford Lhotka (CSLA framework, if you want to do more of your own building. Many of the ideas are incorporated into DevForce) –IdeaBlade contact – Lisa Martin

Building Informix Data- Driven Applications with.Net Sean R. Durity Informix User Forum 2006 Washington, D.C. December 8-9, 2006