Numeric function (learning notes), numeric function learning notes

Numeric function (learning notes), numeric function learning notes

-- ************************************ Digital functions
-- ABS: returns the absolute value.

SELECT ABS(3),ABS(-100) FROM dual;

Result: 3,100
-- CEIL rounded up

SELECT CEIL(3.34343),CEIL(3.932),CEIL(-3.4432),CEIL(-5.9889) FROM dual; 

Result: 4,4,-3,-5.

-- Floor rounded down

SELECT FLOOR(3.34343),FLOOR(3.932),FLOOR(-3.4432),FLOOR(-5.9889) FROM dual; 

Result: 3, 3,-4,-6.

-- Sin --- cosine

SELECT SIN(4),COS(4) FROM dual;

 

-- Power function power (m, n), n power of m

SELECT POWER(2,4) FROM dual;

Result: 16

 

-- Round
-- Verify the use of the round Function

Select round (785.652) does not retain decimal places, ROUND (785.652, 2) retains two decimal places, ROUND (785.652,-1) returns one integer, ROUND (785.352) the first digit of the decimal place is less than 5 rounded off, and the rounded digit (784.652,-1) is less than 5 rounded off FROM dual;

Result: 786,785.65, 790,785,780

-- List the basic information and daily salary of each employee. The daily salary is only kept at 2 decimal places, 30 days per month.

SELECT e. empno, e. ename, e. sal, round (e. sal/30, 2) daily salary FROM emp e;

 

-- Verify that the TRUNC function intercepts uncarried

Select trunc (785.652) does not retain decimal places, TRUNC (785.652, 2) retains two decimal places, TRUNC (785.652,-1) returns one integer, TRUNC (785.352) if the decimal number is retained, TRUNC (784.652,-1) rounds the entire number into a single digit FROM dual;

Result: 785,785.65, 780,785,780

-- Verify MOD for the remainder Function

SELECT MOD(10,3)FROM dual;

Result: 1

-- Square root sqrt

SELECT SQRT(16) FROM dual;

Result: 4