Database Querying: Relational Algebra 1 -- Selections and Projections

In this video we start looking at Relational Algebra -- a fancy term for ways we can combine database tables (relations) to make new tables. A table consists of rows and columns. The first basic operation is the "selection" which pulls out row satisfying some condition (criterion or predicate). The condition can be compound -- often constructed with a Boolean AND or a Boolean OR. The second basic operation is the "projection" which pulls out particular columns (fields, attributes, properties).

Видео Database Querying: Relational Algebra 1 -- Selections and Projections канала Thomas Blum