Re: big un stacking query - help save me from myself

Поиск
Список
Период
Сортировка
От Kevin Grittner
Тема Re: big un stacking query - help save me from myself
Дата
Msg-id 1363378171.8307.YahooMailNeo@web162902.mail.bf1.yahoo.com
обсуждение исходный текст
Ответ на Re: big un stacking query - help save me from myself  (Kirk Wythers <wythe001@umn.edu>)
Список pgsql-general
Kirk Wythers <wythe001@umn.edu> wrote:

> Here is a simplified version of the query approach I am
> attempting.

> CREATE TABLE unstacked_table AS (
>     SELECT
>         var1,
>         var2,
>         var3,
>         MAX (
>             CASE
>             WHEN variable_name = 'unstack1' THEN
>
>             VALUE
>
>             END
>         ) AS unstack1,
>         MAX (
>             CASE
>             WHEN variable_name = 'unstack2' THEN
>
>             VALUE
>
>             END
>         ) AS unstack2,
>         MAX (
>             CASE
>             WHEN variable_name = 'unstack3' THEN
>
>             VALUE
>
>             END
>         ) AS unstack3,
>         MAX (
>             CASE
>             WHEN variable_name = 'unstack4' THEN
>
>             VALUE
>
>             END
>         ) AS unstack4
>     FROM
>         stacked_table
>     GROUP BY
>         variable1,
>         variable2,
>         variable3       
> )
> ;

This is still not making sense to me.  Is VALUE intended to be a
place-holder showing where you have a literal in the code?  If so,
what is the point of using MAX?  Could you create a sample
"stacked" table, insert about 10 rows, and show the SELECT which
would give the "unstacked" form?

--
Kevin Grittner
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


В списке pgsql-general по дате отправления:

Предыдущее
От: Oleg Alexeev
Дата:
Сообщение: Addled index
Следующее
От: Steve Crawford
Дата:
Сообщение: Re: Addled index