this vedio describes
basic relational algebra operations
Selection ( σ ) Selects a subset of rows from a relation.
Projection ( π ) Deletes unwanted columns from a relation.
Cross-Product ( x ) Allows us to combine two relations.
Set-Difference ( - ) Tuples in relation1, but not in relation2.
Union (∪ ) Tuples in relation1 or in relation2.
Intersection (∩) Tuples in relation1 and in relation2
Join( )Tuples joined from two relations based on a condition Using these we can build up sophisticated database queries.
Негізгі бет relational algebra operations in Database Systems በአማርኛ
Пікірлер: 6