Get the count of rows from a COPY command

问题

When copying data from a file, you get the count of rows in psql with the "command tag":

db=# COPY t FROM '/var/lib/postgres/test.sql';
COPY 10

I need the number of rows and would like to avoid a redundant count() on the table.

Is there a way to get this count from COPY directly in a PL/pgSQL function?
As far as I know there is none, but maybe I am missing something?

For PostgreSQL 9.2. But any option in any version would be of interest.

回答1:

Not in PG 9.2, but there is in PG 9.3 courtesy of Pavel (E 1.3.1.7):

Allow PL/pgSQL to access the number of rows processed by COPY (Pavel Stehule)

The command is GET DIAGNOSTICS x = ROW_COUNT.

http://www.postgresql.org/docs/devel/static/release-9-3.html

来源：https://stackoverflow.com/questions/16610449/get-the-count-of-rows-from-a-copy-command