Re: Regex on field value

[Adrian Klaver]

On 04/14/2018 02:06 PM, David G. Johnston wrote:
On Saturday, April 14, 2018, Mike Martin > wrote:


Is this possible, eg
Substring(field, regex include other field name)


Something like?:

select substring(link_key from '^' || c_id  ), link_key, c_id from 
projection where link_key != 'no_key' limit 10;


 substring |  link_key   |  c_id
---+-+
 6RPLF | 6RPLF-1646  | 6RPLF
 6RPLF | 6RPLF-1646  | 6RPLF
 6RPLF | 6RPLF-1646  | 6RPLF
 6RPLF | 6RPLF-1646  | 6RPLF
 4RPLF | 4RPLF-1694  | 4RPLF
 10CEHB| 10CEHB-2628 | 10CEHB
 10CEHB| 10CEHB-2628 | 10CEHB
 10CEHB| 10CEHB-2628 | 10CEHB
 10CEHB| 10CEHB-1698 | 10CEHB
 1GPLF | 1GPLF-1704  | 1GPLF
(10 rows)




Your example doesn't make sense but if you are asking whether a regular 
expression can be stored in a column the answer is yes - though it's 
nothing but a text value with runtime limitations.


David J.




--
Adrian Klaver
adrian.kla...@aklaver.com

Re: Regex on field value

[David G. Johnston]

On Saturday, April 14, 2018, Mike Martin  wrote:

> Is this possible, eg
> Substring(field, regex include other field name)
>

Your example doesn't make sense but if you are asking whether a regular
expression can be stored in a column the answer is yes - though it's
nothing but a text value with runtime limitations.

David J.

Regex on field value

[Mike Martin]

Is this possible, eg
Substring(field, regex include other field name)
Thanks

Re: cursor "x" does not exist

[Adrian Klaver]

On 04/14/2018 09:36 AM, Bob Jones wrote:

On 14 April 2018 at 16:38, Tom Lane  wrote:

Bob Jones  writes:

My apologies if I'm being incredibly stupid here, but I've reviewed
what the docs have to say about naming portals and I still can't see
where I'm going wrong here ?


I think you're forgetting to double-quote an upper case identifier.


FETCH ALL IN B;
ERROR:  cursor "b" does not exist


The cursor is named "B" not "b", but B without quotes folds to the latter.

 regards, tom lane



Thank you tom for showing me the error in my ways.

Now where's that dunce cap gone ?  Maybe I don't deserve to use
anything better than MySQL.   ;-)


Or read the below and be illuminated:)

https://www.postgresql.org/docs/10/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS







--
Adrian Klaver
adrian.kla...@aklaver.com

Re: cursor "x" does not exist

[Bob Jones]

On 14 April 2018 at 16:38, Tom Lane  wrote:
> Bob Jones  writes:
>> My apologies if I'm being incredibly stupid here, but I've reviewed
>> what the docs have to say about naming portals and I still can't see
>> where I'm going wrong here ?
>
> I think you're forgetting to double-quote an upper case identifier.
>
>> FETCH ALL IN B;
>> ERROR:  cursor "b" does not exist
>
> The cursor is named "B" not "b", but B without quotes folds to the latter.
>
> regards, tom lane


Thank you tom for showing me the error in my ways.

Now where's that dunce cap gone ?  Maybe I don't deserve to use
anything better than MySQL.   ;-)

Re: cursor "x" does not exist

[Tom Lane]

Bob Jones  writes:
> My apologies if I'm being incredibly stupid here, but I've reviewed
> what the docs have to say about naming portals and I still can't see
> where I'm going wrong here ?

I think you're forgetting to double-quote an upper case identifier.

> FETCH ALL IN B;
> ERROR:  cursor "b" does not exist

The cursor is named "B" not "b", but B without quotes folds to the latter.

regards, tom lane