Creating a grid in HTML from a database search
Use string.Empty instead of "" to indicate an empty string. It conveys your intent without ambiguity (i.e.: nobody will think you forgot to enter something in the string).



When concatenating in a loop, use a StringBuilder.



Use meaningful names. I don't know what concat and oDrc actually mean. Nor pkunica, but that might be a language-issue (I'd encourage you to stick to English-only).