Philippe Makowski escreveu:

> ok I missed that
>
> but it is only a facility in case you wanted to use same window definition in more than
> one OVER cause
>
>> But one window could reference others and then things become more complex.
>>
> no, windows are independent from each other

With <existing window name> shall be possible to create a window based
on another one.

--------------
<window clause> ::= WINDOW <window definition list>

<window definition list> ::=
<window definition> [ { <comma> <window definition> }... ]

<window definition> ::= <new window name> AS <window specification>

<new window name> ::= <window name>

<window specification> ::=
<left paren> <window specification details> <right paren>

<window specification details> ::=
[ <existing window name> ]
[ <window partition clause> ]
[ <window order clause> ]
[ <window frame clause> ]
--------------

--
Adriano dos Santos Fernandes
http://www.firebirdsql.org