Re: Possible parser bug? .... Re: Picking out the most recent row using a time stamp column

Friday, February 25, 2011, 12:53:08 AM you wrote:

> select distinct on (a, b, c)
> a, b c, time_stamp, value

Without the comma, you declare 'b AS c'

> from data
> order by a, b, c, time_stamp desc;

> The output produced is the same as this query:

> select distinct on (a, b)
> a, b, time_stamp, value
> from data
> order by a, b, time_stamp desc;

the 'c' is optimized away, since it is an alias for b, and thus redundant
for the distinct.

> Not sure if this is considered a parser bug or not, but it feels slightly
> odd not to get an error.

No error, just plain SQL :-)

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