Abstract
The original relational languages such as DSL Alpha used the basic
universal and existential quantifiers in the traditional manner of
mathematical logic, which is not the way in which they are used in
natural languages. When DSL Alpha proved too difficult for use in
a data base language SQL was developed. SQL uses special constructs to
avoid the quantifiers of DSL Alpha but is otherwise similar. SQL is
heavily supported by IBM and other vendors and is becoming the
standard non procedural data base language. Although SQL is clearly
easier to use than DSL Alpha, because it continues to use the equivalent
of the basic quantifiers in the traditional manner of mathematical logic,
for more complex retrievals either an SQL expression is difficult and
contrived or is not possible.
SQL/N permits the basic quantifiers of DSL Alpha but uses them in the
much simpler manner of natural language. In addition it permits the use
of the whole range of natural quantifiers. The result is that SQL/N
expressions mirror their natural language counterparts and are simpler
and more concise than SQL expressions. SQL/N is also upward compatible
with SQL so that simple SQL and SQL/N expressions are identical.
SQL/N can handle all known kinds of associations easily and permits
the use of natural quantifiers with them. In this tutorial we deal
only with the common one to many associations.
Notes
We are currently acquiring citations for the work deposited into this collection. We recognize the distribution rights of this item may have been assigned to another entity, other than the author(s) of the work.If you can provide the citation for this work or you think you own the distribution rights to this work please contact the Institutional Repository Administrator at digitize@ucalgary.ca
