Subject RE: [firebird-support] SQL
Author mohamed hamza
Post date 2019-08-30T22:39:02Z
What do you think about creating view? ( ex :viewAge ) and then we can write
 
select * from viewAge where state='CA'


De : firebird-support@yahoogroups.com <firebird-support@yahoogroups.com> de la part de Richard Damon richard@... [firebird-support] <firebird-support@yahoogroups.com>
Envoyé : mercredi 28 août 2019 05:27
À : firebird-support@yahoogroups.com <firebird-support@yahoogroups.com>
Objet : Re: [firebird-support] SQL
 
 

On 8/5/19 4:20 AM, mohamed hamza medhome@... [firebird-support]
wrote:

>  
>
> Hi All,
>
>   I am new to sql,  I am coming  from  Xbase  system .
>  I want to know if it 's  possible to execute query using last query
> result?
>
> EXAMPLE
>   
> 1  select * from persons where state='CA'
>
> 2 select * from persons where age> 18       but  we  have to use the
> result of 1
>
> I DO NOT WANT TO DO AN AND        (  STATE = 'CA'    AND   AGE > 18  ) ;
>
> Best Regards

Maybe something like:

SELECT * FROM ( SELECT * FROM persons where state = 'CA') where age > 18;

But using AND will generally be faster.

As far as I know, you can't just reference the previous query, unless
you explicitly put that result into a temporary table.

--
Richard Damon