I have a shapefile containing country boundaries for a number of countries in Asia. Many of these countries have hundreds of islands, so that overall there are other 2000 separate features in the attribute table, despite there being only around fifteen countries. The map I am making will show tiger populations and I am planning to shade the countries different colours according to where the population data was obtained from (data source). I was going to input this information on data source manually into a new field in the attribute table. Obviously it would be too time-consuming to do this manually for 2000+ features. Therefore, could someone please tell me if it is possible to combine all the features relating to a single country in the attribute table so I can therefore manually input the data source information once for each country? Or is there any other way someone would recommend to go about this?
Yes, it can be done, however it may in-tall some manual work:
Start edit session on the country layer and manually select all like country polygons per country once all selected, on editor toolbar use Merge tool to merge all features to one feature. Repeat this step for other countries
Start edit session, use Select Layer by Location method to select near features to focus country. You will mostly have to do some manually selecting and un-selecting here around the country boarders. Once all focus country polygons selected repeat Merge step in Option 1.
If the country attribute table already has a name field filled out for all features, you may use the Dissolve tool on that field. This will produce a table of one feature per unique country name.