多项选择题
Examine the description of the STUDENTS table:
STD_ID NUMBER(4)
COURSE_ID VARCHARD2(10)
START_DATE DATE
END_DATE DATE
Which two aggregate functions are valid on the START_DATE column?（）
A. SUM(start_date)
B. AVG(start_date)
C. COUNT(start_date)
D. AVG(start_date, end_date)
E. MIN(start_date)
F. MAXIMUM(start_date)
相关考题
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单项选择题
Which syntax turns an existing constraint on?（）
A. ALTER TABLE table_name ENABLE constraint_name;
B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint_name;
C. ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;
D. ALTER TABLE table_name STATUS ENABLE CONSTRAINT constraint_name;
E. ALTER TABLE table_name TURN ON CONSTRAINT constraint_name; -
单项选择题
Which syntax turns an existing constraint on?（）
A. ALTER TABLE table_name ENABLE constraint_name;
B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;
C. ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;
D. ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name; -
单项选择题
Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: Which statement ensures that a value is displayed in the calculated columns for all employees?（）
A. SELECT last_name, 12*salary* commission_pct FROM emp;
B. SELECT last_name, 12*salary* (commission_pct,0) FROM emp;
C. SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;
D. SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;
