Octavio Alvarez <alvarezp@alvarezp.ods.org> writes:
> In any case, the results are the same as GROUPing BY from the data
> source.
> +-------------+---------+
> | Assignment | Average |
> +-------------+---------+
> | Assignment1 | 94.67 |
> | Assignment2 | 90.33 |
> | Assignment3 | 86.67 |
> +-------------+---------+
>
> A crosstab is not but a presentational transform of the data set. Any
> information you would eventually need can be taken from the original
> data source, one way or another. That's why dynamic-column crosstab are
> not a problem, and the DBMS should not worry about providing the
> information about the columns, maybe by simply not allowing the
> dynamic-column ones in subqueries.
What about a WHERE clause like
WHERE P1 > P2
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
Ask me about EnterpriseDB's RemoteDBA services!
