Oracle table()函数用法

Oracle table()函数用法

Oracle利用table()函数，我们可以将PL/SQL返回的结果集代替table。

1、table()结合数组：

create or replace type t_test as object(
id integer,
rq date,
mc varchar2(60)
);

create or replace type t_test_table as table of t_test;

create or replace function f_test_array(n in number default null) return t_test_table
as
v_test t_test_table := t_test_table();
begin
for i in 1 .. nvl(n,100) loop
v_test.extend();
v_test(v_test.count) := t_test(i,sysdate,'mc'||i);
end loop;
return v_test;
end f_test_array;
/

select * from table(f_test_array(10));

select * from the(select f_test_array(10) from dual);

2、table()结合PIPELINED函数：

create or replace function f_test_pipe(n in number default null) return t_test_table PIPELINED
as
v_test t_test_table := t_test_table();
begin
for i in 1 .. nvl(n,100) loop
pipe row(t_test(i,sysdate,'mc'||i));
end loop;
return;
end f_test_pipe;
/

select * from table(f_test_pipe(20));

select * from the(select f_test_pipe(20) from dual);

3、table()结合系统包：
create table test (id varchar2(20));
insert into test values('1');
commit;
explain plan for select * from test;
select * from table(dbms_xplan.display);

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