The number of rows affected by the PostgreSQL fetch operation

How to get the number of rows affected by the normal operation, PostgreSQL inside has a built-in variable diagnostics and Row_count can do this.

First, the environment:
Db:9.4beta3

Second, prepare:

postgres=# create table test(id int);
CREATE TABLE
postgres=# insert into test select generate_series(1,20);
INSERT 0 20
postgres=# select * from test;
 id 
----
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
(20 rows)

Third, create the function:

CREATE OR REPLACE FUNCTION fun_affect_rows ()
   RETURNS text AS
$ BODY $

declare
v_count int; begin

insert into test values (99), (98);
GET DIAGNOSTICS v_count = ROW_COUNT;
raise notice ‘The amount of data inserted this time%’, v_count;

delete from test where id <15;
GET DIAGNOSTICS v_count = ROW_COUNT;
raise notice ‘the amount of data deleted this time%’, v_count;

update test set id = 100 where id> 90;
GET DIAGNOSTICS v_count = ROW_COUNT;
raise notice ‘the amount of data this update%’, v_count;

return ‘Test completed’;
end;
$ BODY $
   LANGUAGE plpgsql VOLATILE
   COST 100;
ALTER FUNCTION fun_affect_rows ()
   OWNER TO postgres;

Four, operation situation:

postgres = # select * from fun_affect_rows ();
NOTICE: The amount of data inserted this time 2
NOTICE: The amount of data deleted this time 14
NOTICE: The amount of data updated this time 2
  fun_affect_rows
-----------------
  Test finished
(1 row) 

If you want to return the results of DML, then use returning.

v. References
Http://www.postgresql.org/docs/9.0/static/plpgsql-statements.html

The number of rows affected by the PostgreSQL fetch operation