單項選擇題

What does the TRUNCATE statement do?（）

A. Removes the table
B. Removes all rows from a table
C. Shortens the table to 10 rows
D. Removes all columns from a table
E. Removes foreign keys from a table

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單項選擇題

Which is an /SQL*Plus command? （）

A. INSERT
B. UPDATE
C. SELECT
D. DESCRIBE
E. DELETE
F. RENAME

單項選擇題

Which SELECT statement should you use to extract the year from the system date and display it in the format "1998"? （）

A. SELECT TO_CHAR(SYSDATE,'yyyy') FROM dual;
B. SELECT TO_DATE(SYSDATE,'yyyy') FROM dual;
C. SELECT DECODE(SUBSTR(SYSDATE, 8), 'YYYY') FROM dual;
D. SELECT DECODE(SUBSTR(SYSDATE, 8), 'year') FROM dual;
E. SELECT TO_CHAR(SUBSTR(SYSDATE, 8,2),'yyyy') FROM dual;