http://connormcdonald.wordpress.com/2013/09/11/12c-fetch-first/
重复测试：
@ver
BANNER CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production 0
drop table T purge;
create table T as select * from all_objects;
select owner, object_name, object_id from t order by owner, object_name FETCH FIRST 5 ROWS ONLY;
OWNER OBJECT_NAME OBJECT_ID
-------------------- ------------------------------ ----------
APEX_040200 APEX 88917
APEX_040200 APEX$ARCHIVE_CONTENTS 89744
APEX_040200 APEX$ARCHIVE_CONTENTS_IDX1 89748
APEX_040200 APEX$ARCHIVE_HEADER 89742
APEX_040200 APEX$ARCHIVE_HISTORY 89749
variable x number
exec :x := 5
select owner, object_name, object_id from t order by owner, object_name FETCH FIRST :x ROWS ONLY;
OWNER OBJECT_NAME OBJECT_ID
-------------------- ------------------------------ ----------
APEX_040200 APEX 88917
APEX_040200 APEX$ARCHIVE_CONTENTS 89744
APEX_040200 APEX$ARCHIVE_CONTENTS_IDX1 89748
APEX_040200 APEX$ARCHIVE_HEADER 89742
APEX_040200 APEX$ARCHIVE_HISTORY 89749
declare
x number := 5;
begin
for i in (
select owner, object_name, object_id
from t
order by owner, object_name
FETCH FIRST x ROWS ONLY
)
loop
null;
end loop;
end;
/
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Process ID: 2580
Session ID: 128 Serial number: 57
--出现错误！
declare
x number := 5;
begin
for i in (
select owner, object_name, object_id
from t
order by owner, object_name
FETCH FIRST cast(x as number) ROWS ONLY
)
loop
null;
end loop;
end;
/
PL/SQL procedure successfully completed.
--OK 这样通过。