[sc34wg3] TMQL: Grammar "order by clause"

Lars Heuer heuer at semagia.com
Sun Nov 30 15:31:23 EST 2008

Hi all,

The productions [51] "select expression" and [52] "flwr expression"
contain an optional "order by" clause. This is specified as follows:

    order-by-clause ::= 'order' 'by' value-expression (',' value-expression)*

There is no possibility to specify the ordering (ascending / descending).

On the other hand, [24] "tuple expression" provides the "asc" / "desc"
keywords but requires parenthesis:

    tuple-expression ::= '(' value-expression ('asc'|'desc')? (','
value-expression)* ')'

Are the parentheses optional iff a tuple expression contains just one
value expression or is the order-by clause wrong?

Best regards,

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