Song(title, genreCode, cDate) Composer(name, DOB) Writes(composerName, songTitle) Performance (perfName, songTitle, length, perfDate, recorded) Here are the SQL commands used to create the tables, above, mutatis mutandis from before (note: 'T" stands for TRUE and 'F' stands for FALSE) CREATE TABLE Song ( title VARCHAR2(255) PRIMARY KEY, genreCode CHAR (4) cDate DATE /* the date of composition (writing) */ CREATE TABLE Composer ( name VARCHAR2 (50) PRIMARY KEY DOB DATE /*the song writer's birth date */ CREATE TABLE Writes ( composerName VARCHAR2 (50) REFERENCES Composer (name), songTitle VARCHAR2 (255) REFERENCES Song(title) CREATE TABLE Performance ( perfName songTitle length perfDate recorded PRIMARY KEY (songTitle, perfDate) VARCHAR2 (50) VARCHAR2 (255) REFERENCES Song(title), INTEGER CHECK (length > 0), DATE, CHAR(1) CHECK (recorded in ('T','F','?')), /* in seconds *,/