c# postgresql

System.Data.IDbConnection conn = null;
		try {
			conn = com.janoserdelyi.DataSource.ConnectionManager.GetConnection("Nagry");
			
			Npgsql.NpgsqlCommand command = new NpgsqlCommand("insert into article (article_title, article_desc, article_content, active, publish_dt, expire_dt, allow_comments, create_dt, create_author_id, categories) values (:articleTitle, :articleDesc, :articleContent, :active, :publishDt, :expireDt, :allowComments, :createDt, :createAuthorId, :categories); select lastval();", (Npgsql.NpgsqlConnection)conn);
	    
			com.janoserdelyi.DataSource.CommandHelperFactory chf = new com.janoserdelyi.DataSource.CommandHelperFactory(DataSource.DatabaseType.Postgresql);
			com.janoserdelyi.DataSource.ICommandHelper commandHelper = chf.GetHelper();
			commandHelper.Command = command;
			
			commandHelper.Append("articleTitle", articleTitle, 100);
			commandHelper.Append("articleDesc", articleDesc, 300);
			commandHelper.AppendText("articleContent", articleContent);
			commandHelper.Append("active", active);
			commandHelper.Append("publishDt", publishDt);
			commandHelper.Append("expireDt", expireDt);
			commandHelper.Append("allowComments", allowComments);
			commandHelper.Append("createDt", DateTime.Now);
			commandHelper.Append("createAuthorId", createAuthorId);
			commandHelper.Append("categories", categories);
			
			try {
				return command.ExecuteScalar();
			} catch (Exception oops) {
				throw new Exception( "Insert failed to return scalar value. " + oops.Message);
			}
			
		} catch (Npgsql.NpgsqlException) {
			throw;
		} catch (System.Exception) {
			throw;
		} finally {
			try {
				com.janoserdelyi.DataSource.ConnectionManager.Close(conn);
			} catch {}
		}