Can someone explain the below statement to me with an example/sample... basically what i'm trying to do is handle a member couple profile which will have multiple Firstnames, Age, Height, etc about 10 fields will be similar.
You could create duplicate fields, but simply add a single extra field, "coupleId", which would have a unique id for each couple; and two rows (one for each person) per couple; then JOIN the table against itself with a constraint like a.coupleId = b.coupleId AND a.id <> b.id so that you can condense the data into a single result row for a given couple.
I am not following what you are asking here? What is a member couple profile? Are you saying that two members join up as a couple and you want to have both members details appearing on a single returned row?
obviously the table for the people would have one row per person, and you would not want duplicate columns in there
the simplest solution, and in my mind the most elegant, is a separate table, which contains only two columns, the ids of the two people who are dating
204 john smith 42
206 mary white 27
213 todd kamalfeszchuk 37
221 linda brown 28
242 betty boop 45
one of the other questions that always comes up in this database design is how do i prevent duplication, e.g. if john and betty are dating, how do i ensure that i don't have john and betty in the database along with betty and john?
the answer to that is simple, too -- always store the ids with the lower one first