Re: Visibility of table aliases in CTEs

On 16/11/2013 15:48, David Johnston wrote:
> Raymond O'Donnell wrote
>> Hello all,
>>
>> In a WITH query, are table aliases within a CTE isolated from the rest
>> of the query? For example, if I do this -
>>
>>   with my_cte as (
>>     select * from my_table t
>>   )
>>   ....
>>
>> - can I re-use the alias "t" elsewhere in the same query?
>>
>> I had a dig through the appropriate section of the docs, but the answer
>> wasn't obvious to me there.
>
> This seems like one of those "just try it and see what happens" kind of
> question.  But since I'm mobile and cannot run SQL I'll just say that such
> an alias is indeed hidden.  No different than:
>
> Select * from (tbla as alpha natrual join tblb as beta) as ab natural join
> tbla as alpha


Thanks David - I did indeed try it, and it seemed to be the case, but as
I'm not any kind of expert I wanted to make sure that my empirical
results were correct. :-)

Ray.


--
Raymond O'Donnell :: Galway :: Ireland
rod@iol.ie