1.创建游标，且使用select子句指定游标返回的行，分别使用FETCH抓取数据，MOVE重定位游标

omm=# start transaction;
omm=# CURSOR cursor1 FOR SELECT * FROM tpcds.reason ORDER BY 1;
omm=# select * from pg_cursors;
omm=# fetch forward 2 from cursor1;
omm=# MOVE FORWARD 3 FROM cursor1;

2.在系统视图pg_cursors中查看游标

omm=# select * from pg_cursors;

3.创建一个使用游标的存储过程

create or replace procedure test_cursor_1
as
    company_name    varchar(100);
    company_loc varchar(100);
    company_no  integer;

    cursor c1_all is --cursor without args
        select name, loc, no from company order by 1, 2, 3;
begin
    if not c1_all%isopen then
        open c1_all;
    end if;
    loop
        fetch c1_all into company_name, company_loc, company_no;
		RAISE INFO 'company_name: %' ,company_name;
        exit when c1_all%notfound;
    end loop;
    if c1_all%isopen then
        close c1_all;
    end if;
end;
/
call test_cursor_1();

4.清理数据

drop schema tpcds cascade;
drop table company;