On 2022-03-03 10:10, Peter Eisentraut wrote:
On 02.03.22 20:12, Jille Timmermans wrote:
On 2022-02-28 11:13, Peter Eisentraut wrote:
On 27.02.22 10:42, Jille Timmermans wrote:
I wanted to be able to allocate a bunch of numbers from a sequence
at once. Multiple people seem to be struggling with this
(https://stackoverflow.com/questions/896274/select-multiple-ids-from-a-postgresql-sequence,
https://www.depesz.com/2008/03/20/getting-multiple-values-from-sequences/).
I propose to add an extra argument to nextval() that specifies how
many numbers you want to allocate (default 1).
What is the use of this?
I note that the stackoverflow question wanted to return multiple
sequence values as a result set, whereas your implementation just
skips a number of values and returns the last one. At least we
should
be clear about what we are trying to achieve.
Both would work for me actually. I'm using COPY FROM to insert many
rows and need to know their ids and COPY FROM doesn't support
RETURNING.
I don't understand this use case. COPY FROM copies from a file. So
you want to preallocate the sequence numbers before you copy the new
data in?
Yes
How do you know how many rows are in the file?
I'm using https://pkg.go.dev/github.com/jackc/pgx/v4#Conn.CopyFrom,
which uses the COPY FROM protocol but doesn't actually have to originate
from a file.
