SQL Tutorial - Expressing 'FOR ALL' via 'NOT EXISTS NOT' | Database Tutorial 5j

In this lecture of the databases course we learn how to express "for all" in SQL. While there is an EXISTS operator, there is no FORALL in SQL. We will see how "for all" can be expressed in SQL by using EXISTS. For reasoning about and transforming queries, it is often helpful to use predicate logic.

This is the databases online course given at the Vrije Universiteit Amsterdam by Jörg Endrullis. The course objective is to obtain a good understanding of relational database systems from the user perspective. This includes the ability to develop conceptual database models, as well as key concepts and skills in relational database theory and practice.

Among others, we treat in this course the following subjects:
(a) entity–relationship diagrams for the design of database schemata,
(b) the relational database model and integrity constraints,
(c) SQL (structured query language) for retrieving information from relational databases,
(d) database normalisation and functiona dependencies (reasoning about good database design),
(e) transactions and concurrency control.

The slides are based on work by Peter Boncz and Torsten Grust.

[forestsunrise]

Thanks a lot! I have to make a presentation about the universal quantifier in SQL and this is exactly what I need!