to manipulate rows and cells in the TDBGrid component ?
Note that you are saying TDBGRID, which it is a component for be used to edit data in tables from a database; this mean this is used for edit records from data stored in disk in form of popular databases, like Dbase, paradox, MSacces, SQLs etc.

If that is wath you want to do then you have to use the datasource property to link tdbgrid with a TDATASOURCE component, and this one have to be linked with a TDATASET component where is defined which datababase and table is going to be opened.

If what you want in your program is just show/edit some data in tabular way then use STRINGGRID component (found in the additional pallete) instead, this one allow you to manipulate string data using rows and colums.

good luck.