1. Consider the design of a database for a web site of jokes. Each joke is identified by a unique joke ID, a title, a description of the joke, the date the joke is posted, and a list of tags (each tag is a single word in lower cases). Only registered users can post, read, comment on jokes. Each registered user is identified by a user ID, a password, a first name, a last name, an email, the gender, and his/her age. A user can give at most one review for each joke, and on a particular day, the user can post at most 5 jokes and 5 reviews. Meanwhile, a joke can have no or many reviews. The review given by a user provides a score of "Excellent, Good, fair, or or" and then a short remark. A user can modify an existing review that she/he gave earlier. One special user called "root" is designated as the administrator user. The root user can ban any other user into a black list. Once banned, a user will not be able to login into the system unless he/she is unbanned from the blacklist subsequently. In addition, each user has two dynamic lists: my favorite friends and my favorite jokes, which can be modified by the user when necessary by insert, delete or update. for the system, in particular, use arrows or thick lines to represent constraints appropriately. Write down your assumptions and justifications a). Draw an E-R diagram briefly and clearly. b). Translate the above E-R diagram into a relational model, i.e., write a set of TABLE statements. In particular, specify primary key, foreign key and other constraints whenever possible