I have a shapefile made of buildings, each one of them characterized by some attributes. I need to add some attributes contained in a .dbf file. The two files have in common the attribute "ID", so the information contained in the .dbf could be related to the building having the same ID. Currently I do this through OPENOFFICE, but I have a problem, because not all the buildings contained in the shapefile have the properties defined in the .dbf.
It is good practice never do any operations on shape's structure outside of a GIS environment. If you're are using Quantum GIS I strongly recommend to add the DBF table to qgis, and then use "join function" with,for example, "left join". So I advise you to take a look at Qgis documentation and tutorials like this.