Home » Oracle » 1z0-061 v.2 » Which statement is true regarding the UNION operator?
Which statement is true regarding the UNION operator?
A. By default, the output is not sorted.
B. Null values are not ignored during duplicate checking.
C. Names of all columns must be identical across all select statements.
D. The number of columns selected in all select statements need not be the same.
Correct Answer: D
Explanation/Reference:
Explanation:
The SQL UNION query allows you to combine the result sets of two or more SQL SELECT statements. It removes duplicate rows between the various
SELECT statements. Each SQL SELECT statement within the UNION query must have the same number of fields in the result sets with similar data types.
Download Printable PDF. VALID exam to help you PASS.
|
|