OCP 19c 认证1Z0-082考试题库（第2题）【2020】-CUUG内部学员版082题库解析
2.Which statement is true about the INTERSECT operator used in compound queries?
A. Multiple INTERSECT operators are not possible in the same SQL statement
B. It processes NULLs in the selected columns
C. INTERSECT is of lower precedence than UNION or UNION ALL
D. It ignores NULLs
Answer: B
(解析：为了符合新出现的 SQL 标准，Oracle 的未来版本将赋予 INTERSECT 运算符比其他 set运算符更高的优先级。因此，在使用 INTERSECT 运算符和其他集合运算符的查询中，应该使用括号来指定求值顺序。INTERSECT 不会忽略空值。)