How to learn ADO.NET

How to learn ADO.NET "I need to learn ADO.NET to build applications based on MS Office. I have read a good deal about ADO.NET in the MSDN Library, but everything seems rather messy to me. What are the basics one must figure out when using ADO.NET? I think a few key words will suffice to let me organize my learning."
Asked by: Guest \| Views: 239

Total answers/comments: 2

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Guest [Entry]

"There are three key components (assuming ur using SQL server):

SQLConnection
SqlCommand
SqlDataReader

(if you're using something else, replace Sql with ""Something"", like MySqlConnection, OracleCommand)

Everything else is just built on top of that.

Example 1:

using (SqlConnection connection = new SqlConnection(""CONNECTION STRING""))
using (SqlCommand command = new SqlCommand())
{
command.commandText = ""SELECT Name FROM Users WHERE Status = @OnlineStatus"";
command.Connection = connection;
command.Parameters.Add(""@OnlineStatus"", SqlDbType.Int).Value = 1; //replace with enum
connection.Open();

using (SqlDataReader dr = command.ExecuteReader))
{
List<string> onlineUsers = new List<string>();

while (dr.Read())
{
onlineUsers.Add(dr.GetString(0));
}
}
}

Example 2:

using (SqlConnection connection = new SqlConnection(""CONNECTION STRING""))
using (SqlCommand command = new SqlCommand())
{
command.commandText = ""DELETE FROM Users where Email = @Email"";
command.Connection = connection;
command.Parameters.Add(""@Email"", SqlDbType.VarChar, 100).Value = ""user@host.com"";
connection.Open();
command.ExecuteNonQuery();
}"

Guest [Entry]

"Another way of getting a command object is to call connection.CreateCommand().

That way you shouldn't have to set the Connection property on the command object."