Which two statements are true regarding the COUNT function? (Choose two.)
A.
The COUNT function can be used only for CHAR, VARCHAR2 and NUMBER data types
B.
A SELECT statement using COUNT function with a DISTINCT keyword cannot have a
WHERE clause
C.
COUNT(DISTINCT inv_amt) returns the number of rows excluding rows containing
duplicates and NULL values in the INV_AMT column
D.
COUNT(cust_id) returns the number of rows including rows with duplicate customer IDs
and NULL value in the CUST_ID column
E.
COUNT(*) returns the number of rows including duplicate rows and rows containing
NULL value in any of the columns
Explanation:
In my opinion correct are D and F.
C and F Correct
update employees set FIRST_NAME = NULL where last_name like ‘%al%’;
select count(distinct manager_id) from employees
where HIRE_DATE>sysdate -4200;
select count(first_name) from employees
where HIRE_DATE>sysdate -4200;
select *
from employees
where HIRE_DATE>sysdate -4200;
select count(*) from employees
where HIRE_DATE>sysdate -4200;
select *
from employees;
C and E (not F)
Y not c??
Sorry y not D??