... ROUND(4.9 23, 1), ROUND(4.9 23) , ROUND(4.9 23, -1), ROUND(4.9 23, 2) FROM DUMMY; ROUND(4.9 23, 1) ROUND(4.9 23) ROUND(4.9 23, -1) ROUND(4.9 23, 2) 4.9 5 0 4.92 Ví dụ hàm TRUNC(n[,m]) SELECT TRUNC (4.9 23, 1), ... =10; SAL SQRT(SAL) SQRT(40) SQRT(COMM) 5000 70.7106781 6 .32 455 532 2450 49.4974747 6 .32 455 532 130 0 36 .0555128 6 .32 455 532 Ví dụ hàm SIGN(n) SELECT SAL-NVL(COMM,0), SIGN(SAL-NVL(COMM,0)), ... 7 839 09-06-1981 2450 10 7902 FORD ANALYST 7566 03- 12-1981 30 00 20 7566 JONES MANAGER 7 839 02-04-1981 2975 20 7 839 KING PRESIDENT 17-11-1981 5000 10 7 934 MILLER CLERK 7782 23- 01-1982 130 0...