In computer science, domain relational calculus is a calculus that was introduced by Edgar F. Codd as part of the relational model in order to give a declarative database query language for this data model.
A DRC Query has the form:
This language uses the same operators as tuple calculus; Logicial operators ∧ (and), ∨ (or) and ¬ (not), and we can use the existential quantifier (∃) and the universal quantifier (∀) to bind the variables.
Here are examples of DRC:
Let's take A,B1,C to mean Rank, Name, ID and D,E,F to mean Name, DeptName, ID
Find all Captains of the Enterprise:
Find Names of Enterprise crewmembers who are in Stellar Cartography: