SQL field with multiple id's of other table

Question

Could someone give me an idea how to create this database structure. Here is an example:

Table \"countries\":
id, countryname
1, \"US\"
2, \"DE\"
3, \"FR\"
4         


        

Answer 1

Without denormalizing, you'll need to add an extra table

Table Product countries
ProductID CountryID
1         1
1         2
1         4...