Question

I can connect to MySQL database from my WinForms app fine. The question is once I am logged in how can I perform multiple select statements without having to login again?

MySqlConnection connection = new MySqlConnection(MyConString);
connection.Open();

MySqlCommand command = connection.CreateCommand();
MySqlDataReader Reader;

command.CommandText = "select id from user ";

Then I want to perform a select statement for another table without having to create connection again.
How do I dothis?
I can’t seem to just do connection.CreateCommand.

Answer 1

As long as the queries are within the same block, you can use the same connection.. However, once closed, you need to re-open it.

using( YourConnectionObject )
{
   ... open connection ...
   ... create your sql querying object... and command 
   SQLCommand.Connection = YourConnectionObject;

   Execute your Query

   SQLCommand.CommandText = "a new sql-select statement";

   Execute your NEW query while connection still open/active

   SQLCommand.CommandText = "a third sql-select statement";

   Execute your THIRD query while connection still open/active

   ... close your connection
}

However, in your application, you can have a single “connection” object like at the application level, or at a form level with the necessary login / connection settings stuff. Then, internally to each form, you can

Open
Run Query
Run Query
Run Query
Close

as needed.