Closes the connection to the database. This is the preferred method of closing any open connection.
Assembly: System.Data (in System.Data.dll)
The connection-level error that occurred while opening the connection.
The method rolls back any pending transactions. It then releases the connection to the connection pool, or closes the connection if connection pooling is disabled.
An application can call more than one time. No exception is generated.
If the DbConnection goes out of scope, it is not closed. Therefore, you must explicitly close the connection by calling Close or Dispose, which are functionally equivalent. If the connection pooling value Pooling is set to true or yes, this also releases the physical connection.
Do not call Close or Dispose on a Connection, a DataReader, or any other managed object in the Finalize method of your class. In a finalizer, you should only release unmanaged resources that your class owns directly. If your class does not own any unmanaged resources, do not include a Finalize method in your class definition. For more information, see Garbage Collection.