sql_macro_19_6_20200129.sql

drop table t;
drop table t1;
drop table t2;

CREATE OR REPLACE FUNCTION sample(t DBMS_TF.Table_t, how_many number DEFAULT 5)
RETURN VARCHAR2 SQL_MACRO
AS 
BEGIN 
  RETURN q'[SELECT * 
              FROM t
	     WHERE rownum <= how_many]';
END sample;
/

create table t
as
select n
  from xmltable('1 to 10'
	 columns
	   n int path '.');

create table t1
as
select n,
       'val_'||to_char(n, 'fm00') val
  from xmltable('1 to 10'
	 columns
	   n int path '.');

create table t2
as
select 'val_'||to_char(n, 'fm00') s
  from xmltable('1 to 10'
	 columns
	   n int path '.');

select * from t1;
select * from t2;

select *
  from sample(t1, 3);

select *
  from sample(t1);

select *
  from sample(t2);