Brug af aggregeringsfunktion til at filtrere post baseret på MIN tidsstempel

Der er flere måder at få den tidligste post og undgå at skulle indtaste de samme kriterier to gange.

Brug af FETCH FIRST ROWS (tilgængelig fra Oracle 12c)

select * 
from abc_customer_details cd
join abc_customers c on c.id = cd.customer_id
where cd.country_code = 'KE'
order by creation_timestamp
fetch first row only;

Brug af en CTE (WITH-klausul)

with cte as
(
  select * 
  from abc_customer_details cd
  join abc_customers c on c.id = cd.customer_id
  where cd.country_code = 'KE'
)
select *
from cte
where (creation_timestamp) = (select min(creation_timestamp) from cte);

Brug af vinduesfunktioner

select *
from
(
  select cd.*, c.*, min(creation_timestamp) over () as min_creation_timestamp
  from abc_customer_details cd
  join abc_customers c on c.id = cd.customer_id
  where cd.country_code = 'KE'
)
where creation_timestamp = min_creation_timestamp;

(Jeg har i øvrigt ændret tilslutningskriterierne i alle disse forespørgsler. Det virker bare ekstremt usandsynligt, at du vil deltage på abc_customer_details.id = abc_customers.customer_id .)