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Informix User Forum 2006
Building Informix DataDriven Applications with .Net
Sean R. Durity
Manager of IT
CornerCap Investment Counsel
Washington, D.C.
December 8-9, 2006
Agenda
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The IBM Informix ADO.Net Driver
ADO.Net Driver Basics (with examples)
Building A Real Application (demo)
Q&A
The Informix ADO.Net Driver
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Current version is Client SDK 2.90TC6
Now installed by default, must have .Net framework 1st
(works with either 1.1 or 2.0 framework)
Namespace is IBM.Data.Informix - reference the library
IBM.Data.Informix.dll
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Client SDK must be installed on any client that will use
the driver (not self-contained in the .dll)
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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.)
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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 www.iiug.org (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 bidirectional
• Data caching and lazy instantiation
• Can’t make DataSets “global” and still use designeraided 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 3rd 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 (www.ideablade.com),
especially read the Concepts Guide!
– DevForce user group (www.ibrunner.com)
– Expert C# 2005 Business Objects, 2nd 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
([email protected])
Informix User Forum 2006
Building Informix DataDriven Applications with .Net
Sean R. Durity
[email protected]
Washington, D.C.
December 8-9, 2006