Each elder, when learning is essentially a database associated with today, in the system will use the drop-down list, such as gender (male/female), such as project type (tennis, football, basketball... ), corresponding database field, it is to use the check constraint set value range, or with a child table T_Sex, T_ProjectType to link, in addition to see some blog posts, said a foreign key to use less (or no), also don't understand, so the two problems:
1 case with what method to record the drop-down, or other appropriate method?
2. The foreign key in a large database design can use?
Consult, thank you