How can I link an external database(say access/oracle) to a drawing so that I m able to insert/update attribute directly from the autocad map drawing.
>> How can I link an external database
That could be done using the command _DBCONNECT (>>>details<<<)
Using Map3D you can also use the command _MAPCONNECT (check >>>here<<<) to connect to a database.
>> I m able to insert/update attribute directly from the autocad map drawing
That is what I don't understand! What records do you have in your database and how are they set in relation to AutoCAD-objects? Who or what creates the relation between AutoCAD-blocks/attribtues to the database? When should you AutoCAD-BlockAttributes be updated? .... So please describe a little bit more detailed what you like to get and - as this is a development forum - what code makes you troubles.
If you have troubles just to connect to a database from dotNET then you can search the www for OLEDB and you will get millions of sample codelines.
- alfred -