Consider the SOCIAL NETWORK relational database schema description provided below which is used to to manage a social network. The relations are: PERSON (NickName, FullName, BirthDate) . POST (PostID, PersonNick, WallPersonNick, Datetime, Content) . FRIENDS (PersonNick1, PersonNick2) LIKE (PostID, PersonNick, Datetime, LikeType) LIKETYPE (LikeType, LikeName) COMMENT (CommentlD, PostID, PersonNick, Datetime, Text) PRIVATE_MESSAGE (MessagelD, PersonNick1, PersonNick2, Datetime, Text, Read) 2. (5 points each) Write the following queries in SQL, using the schema provided above. (Note: Your queries must not be "state-dependent", that is, they should work without modification even if another instance of the database is given.)