Dot Net WindowsForms Question:

You have to get the "dotnet driver" of the database (or any
other datasource) you want to access to.

For example:
MySQL: Connector/Net
Access: Microsoft Access Driver
Oracle: Oracle Data Access Components (ODAC)

Afterwards you build a connection string to tell your
programm which driver you want to use and where the
datasource can be found, for example:

public const string DB_CONN_STRING =
"Driver={Microsoft Access Driver (*.mdb)}; "+
"DBQ=D:\\CS\\TestDbReadWrite\\SimpleTest.mdb";

Afterwards you just have to open a connection to the
database using the previously created connection string and
send a query to the database to get the record:

ADOConnection conn = new ADOConnection(DB_CONN_STRING);
conn.Open();
ADODataReader dr;
ADOCommand cmd = new ADOCommand( "SELECT * FROM <table>",
conn );
cmd.Execute(out dr);
while (dr.Read()){
....}