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  • 【2019年8月版】OCP 071认证考试原题-第38题

    choose two.

    You need to calculate the number of days from 1st January 2019 until today.

    Dates are stored in the default format of DD-MON-RR.

    Which two queries give the required output?

    A) SELECT SYSDATE - TO_DATE (' 01-JANUARY-2019' ) FROM DUAL;

    B) SELECT TO_DATE (SYSDATE, ' DD/MONTH/YYYY' ) - '01/JANUARY/2019' FROM DUAL;

    C) SELECT ROUND (SYSDATE - TO_DATE(' 01/JANUARY/2019' ) ) FROM DUAL;

    D) SELECT TO_CHAR (SYSDATE, ' DD-MON-YYYY') - '01-JAN-2019' FROM DUAL;

    E) SELECT ROUND (SYSDATE- '01-JAN-2019') FROM DUAL:

    Answer:AC

    (解析:在进行日期计算的时候需要用转换函数把字符型的转换成日期型,oracle 不会隐式转换。)

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  • 原文地址:https://www.cnblogs.com/cnblogs5359/p/11940092.html
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