次のコマンドを実行します。 SQL> DEFINE採用日= '01 -APR -2011 '; SQL> SELECT employee_id、first_name、salary FROM employees WHERE Hire date>&hiredate AND manager_id>&mgr_id; どの置換変数に対してプロンプトが表示されますか?
正解:D
* D. only &mgr_id: Since the hiredate variable is already defined before the SELECT statement, you will not be prompted for &hiredate again. However, &mgr_id has not been defined, so you will be prompted for this substitution variable.