While going over the language reference to do some manual fixes, I came
across the following caution (see
https://firebirdsql.org/file/documentation/reference_manuals/fblangref25-en/html/fblangref25-dml-select.html#fblangref25-dml-select-orderby-unions
"""
Expressions whose calculation results are non-negative integers will be
interpreted as column position numbers and will cause an exception if
they fall outside the range from 1 to the number of columns.
Example:
SELECT
X, Y, NOTE
FROM PAIRS
ORDER BY X+Y DESC
* The number returned by a function or a procedure is unpredictable,
regardless of whether the sort order is defined by the expression itself
or by the column number
* Only non-negative integers are interpreted as column numbers
* An integer obtained by one-time evaluation of an expression or by
parameter substitution is saved as a constant, because this value
applies to all rows.
"""
I just tested this in Firebird 2.5 and 1.5, and this is not actually the
case (and I would be surprised if it ever has been the case). The value
of an expression itself is used to sort. As far as I'm aware only
literal or parenthesized literal values can be used to identify column
positions.
Any objections if I just remove this caution in the new version?
Mark
--
Mark Rotteveel
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