CommandType can be one of the following values: Text, StoredProcedure, TableDirect.
When the value is CommandType.Text, the property CommandText should contain text of a query that must be run on the server.
When the value is CommandType.StoredProcedure, CommandText property must be a name of a procedure to execute.
When the value is set to TableDirect, CommandText must be name of a table you want to get all data from. All rows and columns are retrieved.
dotConnect for PostgreSQL supports named and unnamed parameters. Parameters of stored procedures can be used only as input, output values will be ignored.