Oracle Database SQL — Question 71

Examine this query:
SELECT SUBSTR(SYSDATE, 1, 5) "Result" FROM DUAL;

Which statement is true?

Answer options

• A. It fails unless the expression is modified to SUBSTR(TO_CHAR(SYSDATE), 1, 5).
• B. It fails unless the expression is modified to SUBSTR(TO_CHAR(TRUNC(SYSDATE), 1, 5).
• C. It fails unless the expression is modified to TO_CHAR(SUBSTR(SYSDATE), 1, 5)).
• D. It executes successfully with an implicit data type conversion.

Correct answer: D

Explanation

The query executes successfully because Oracle performs an implicit data type conversion from a date to a string when using the SUBSTR function. The other options suggest modifications that are not necessary, as the query does not actually fail due to the implicit conversion that takes place.