Study
CS-315 route
Unit 4 · Lesson 3 of 4 12 min

Relational Algebra: Selection, Projection and Rename

Three operations that cut a table horizontally, cut it vertically, and give the pieces new names.

What this unit covers

Unit 4: The Relational Model and Relational Algebra

  1. 1 The Relational Model: Relations, Tuples, Attributes and DomainsA table looks ordinary, but in Codd's model it is a mathematical set with strict rules. · 11 min
  2. 2 Relational Keys and Integrity ConstraintsSuperkeys, candidate keys, primary keys and foreign keys, and the two rules that stop a database contradicting itself. · 13 min
  3. 3 Relational Algebra: Selection, Projection and RenameThree operations that cut a table horizontally, cut it vertically, and give the pieces new names. · 12 min
  4. 4 Relational Algebra: Set Operations, Joins and DivisionCombining two tables is where the real questions get answered, and where the classic slips happen. · 14 min