Books:
Ramakrishnan and Gehrke	"Database Management Systems 2nd edition, McGraw-Hill, 2000	This is typically used in cs432 and cs433. I've used chapters 4 and 5 in preparing the initial material for this course, and the first homework was taken from chapter 4.
Silberschatz, Korth and Sudarshan	"Database System Concepts, 3rd edition", McGraw-Hill, 1996	This is given as a resource for the graduate Q-exam, but has a nice precise treatment with definitions of some of the early material. Chapters 3 and 4 roughly mirror DMS, though they give algebraic extensions to relational algebra in chapter 3, and set up a more explicitly formal framework from which to embark on SQL.
Celko	"SQL for Smarties: Advanced SQL Programming, 2nd edition", Morgan Kaufman, 2000	This assumes some prior exposure to SQL, but gives a nice and direct approach.