【优技教育】Oracle 19c OCP 082题库(Q 5题)- 2024年修正版
考试科目：1Z0-082
考试题量：90
通过分数：60%
考试时间：150min
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第5题：
5、Choose two.
Which two are true about queries using set operators such as UNION?
A) An expression in the first SELECT list must have a column alias for the expression.
B) In a query containing multiple set operators, INTERSECT always takes precedence over UNION and UNION ALL.
C) Queries using set operators do not perform implicit conversion across data type groups (e.g. character, numeric).
D) CHAR columns of different lengths used with a set operator return a VARCHAR2 whose length equals the longest CHAR value.
E) All set operators are valid on columns of all data types.
Answer：CD
(解析：有关 set operator 的考点很多，经过实验 C 答案是对的，不会进行隐式转换;当列的长度不一样时，以最长的为准，都能够显示内容。)
Oracle 19c OCP认证需要到Oracle指定的WDP机构，有了培训记录之后才能考试，考试需要考2科，分别是082(60%及格)和083(57%及格)，两科都通过之后才能拿到证书。证书如下：
