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From Michael Watzek <mwa.t...@spree.de>
Subject Assertion A14.6.9-7
Date Mon, 07 Nov 2005 15:43:42 GMT
Hi Craig,

assertion A14.6.9-7 specifies:

"A14.6.9-7 [If the returned value from a query specifying a result is 
null, this indicates that the expression specified as the result was 
null.] Note that the semantics of this result are different from the 
returned value where no instances satisfied the filter."

Is my understanding right that the assertion checks if the result 
expression evaluates to null? Does it make sense to test 3 queries, one 
unique query and two non-unique queries, e.g.:

1) SELECT UNIQUE manager FROM Employee WHERE lastname == 'emp2Last'

expected result: null

2) SELECT manager FROM Employee WHERE lastname == 'emp2Last'

expected result: {null}

3) SELECT DISTINCT manager FROM Employee

expected result: {"emp2", null}

Michael Watzek                  Tech@Spree Engineering GmbH
mailto:mwa.tech@spree.de        Buelowstr. 66
Tel.:  ++49/30/235 520 36       10783 Berlin - Germany
Fax.:  ++49/30/217 520 12       http://www.spree.de/

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