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4/5/98


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Table of Contents

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Union, Intersection, Difference

Example

Example (II)

Bag Semantics of SQL

Bag Union

Bag Intersection

Bag Difference

Laws for Bags Differ From Laws for Sets

Example

Forcing Set/Bag Semantics

Forcing Set/Bag Semantics (II)

Example

Aggregations

Example

Eliminating Duplicates Before Aggregation

Grouping

Example

Example

Restriction on SELECT Lists With Aggregation

Example

Problem

HAVING clauses

Example

Example (II)

DB Modifications

Example

Insertion of the Result of a Query

Example

Example (II)

Example (III)

Deletion

Example

Example

Example

Semantics is tricky.

Semantics is tricky.(II)

Updates

Example

Example

Author: Gary L. Burt

Email: burt@umbc

Home Page: www.cs.umbc.edu/~burt