[[Property:title|ADO.NET Sample]]
[[Property:weight|0]]
[[Property:uuid|45d24893-63d0-c2a9-9f62-ead08ca4b901]]
This sample consist of a command line showing how to interact with a database.

The DataReader object is somewhat synonymous with a read-only/forward-only cursor over data. The DataReader API supports flat as well as hierarchical data. A DataReader object is returned after executing a command against a database. The format of the returned DataReader object is different from a recordset. For example, you might use the DataReader to show the results of a search list in a web page.

==Compiling==

To compile the example:   
# Launch EiffelStudio.
# Select '''Use existing Ace (control file)''' and click '''OK'''
# Browse to ''$ISE_EIFFEL\examples\dotnet\ado\ado3\''
# Choose the Ace file for the version of the .net framework you are running
# Choose the directory where the project will be compiled, by default the same directory containing the Ace file.
# Click '''OK'''.


==Running==

After you launch the sample, the following output appears:
<code>
Customer ID    Company Name
ALFKI    Alfreds Futterkiste
ANATR    Ana Trujillo Emparedados y helados
ANTON    Antonio Moreno Taquera
AROUT    Around the Horn
BERGS    Berglunds snabbkp
BLAUS    Blauer See Delikatessen
BLONP    Blondesddsl p`re et fils
BOLID    Blido Comidas preparadas
BONAP    Bon app'
BOTTM    Bottom-Dollar Markets
BSBEV    B's Beverages
CACTU    Cactus Comidas para llevar
CENTC    Centro comercial Moctezuma
CHOPS    Chop-suey Chinese
COMMI    Comrcio Mineiro
CONSH    Consolidated Holdings
DRACD    Drachenblut Delikatessen
DUMON    Du monde entier
EASTC    Eastern Connection
...	...	...
WILMK    Wilman Kala
WOLZA    Wolski  Zajazd
</code>

When the display is finished, the application wait for you to pressed the return key to finish the application.

==Under the Hood==

This application shows how to interact with a database. First the connection to the database is opened:
<code>
            create connection.make ("server=(local)\NetSDK;Trusted_Connection=yes;database=northwind")
</code>
Then a request to the database is made: 
<code>
            create command.make ("select * from customers", connection)
            connection.open
            reader := command.execute_reader
</code> 
Finally, the result of the request is displayed:
<code>
            from
                ok := reader.read
            until
                not ok
            loop
                io.put_string (reader.item ("CustomerID").to_string)
                io.put_string ("%T%T")
                io.put_string (reader.item ("CompanyName").to_string)
                io.new_line
                ok := reader.read
            end
</code>

This sample uses the following ADO.NET classes: 
*  <eiffel>SQL_DATA_READER</eiffel> 
*  <eiffel>SQL_CONNECTION</eiffel> 
*  <eiffel>SQL_COMMAND</eiffel> 

==Notes==

This sample is translated from the example located in the QuickStart\howto\samples\adoplus subdirectory of the .NET Framework SDK samples directory of Microsoft Visual Studio .NET.