Oracle Digital functions

numeric functions
1, take the whole function (ceil up, floor down rounding)
Select Ceil (66.6) N1,floor (66.6) N2 from dual;

2, exponentiation (Power) and square root (sqrt)
Select Power (3,2) n1,sqrt (9) N2 from dual;

3, redundancy
Select mod (9,5) from dual;

4, returns a fixed number of decimal digits (round: Rounding, Trunc: direct truncation)
Select Round (66.667,2) N1,trunc (66.667,2) N2 from dual;

5, the sign of the return value (positive return is 1, negative number is-1)
Select sign ( -32), sign (293) from dual;

Other functions
1.user:
Returns the user name of the login
Select User from Dual;

2.vsize:
The number of bytes required to return an expression
Select Vsize (' HELLO ') from dual;

3.NVL (EX1,EX2):
EX1 value is null returns EX2, otherwise the value itself is returned EX1 (common)
Example: If an employee does not have a commission, 0 is displayed, otherwise the Commission is displayed
Select COMM,NVL (comm,0) from EMP;

4.nullif (EX1,EX2):
value is equal to NULL, otherwise the first value is returned
Example: If wages and commissions are equal, the display is empty, otherwise the wages are displayed
Select Nullif (Sal,comm), sal,comm from EMP;

5.COALESCE:
Returns the first non-empty expression in a list
Select Comm,sal,coalesce (comm,sal,sal*10) from EMP;

6.NVL2 (EX1,EX2,EX3):
If Ex1 is not empty, display ex2, otherwise ex3
such as: View the names of employees with commissions and their commissions
Select NVL2 (Comm,ename, ') as Havecommname,comm from EMP;
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Oracle Digital functions