错误：42883：函数pro_zone_delete（文本）不存在

Question

  

消息：错误：42883：函数pro_zone_delete（文本）不存在

每次我想运行以下代码时都会发生此错误。我错过了什么？我真的很累，发现错误。请帮帮我。 谢谢。 这是函数......

CREATE OR REPLACE FUNCTION sylvia.pro_zone_delete(
    p_ZoneCode text)
    RETURNS void
    LANGUAGE 'plpgsql'
AS $BODY$
begin
  delete from zone where zonecode = p_ZoneCode;
end;
$BODY$;
ALTER FUNCTION sylvia.pro_zone_delete(text)
    OWNER TO postgres;

this is the C# code..

    NpgsqlCommand cmd = new NpgsqlCommand();
                cmd.CommandText = "pro_zone_delete";
                cmd.CommandType = CommandType.StoredProcedure;

                if (cmd == null) return UtilDL.GetCommandNotFound();

                foreach (SiteDS.ZoneRow row in sitDS.Zone.Rows)
                {
                    cmd.Parameters.Add("p_ZoneCode", row.ZoneCode);
                    bool bError = false;
                    int nRowAffected = -1;
                    nRowAffected = ADOController.Instance.ExecuteNonQuery(cmd, connDS.DBConnections[0].ConnectionID, ref bError);