ocp-051-3

一、原题

You need to extract details of those products in the SALES table where the PROD_ID column contains the string '_D123'.
Which WHERE clause could be used in the SELECT statement to get the required output?
A. WHERE prod_id LIKE '%_D123%' ESCAPE '_'
B. WHERE prod_id LIKE '%\_D123%' ESCAPE '\'
C. WHERE prod_id LIKE '%_D123%' ESCAPE '%_'
D. WHERE prod_id LIKE '%\_D123%' ESCAPE '\_'

         答案 B

二、题目翻译
     要从SALES表中提取出PROD_ID列包含'_D123'字符串的产品明细。
     下面哪一个WHERE条件子句可以获得所需的输出结果？

三、题目解析
      ESCAPE子句为指定转译字符，因为'_'下画线在LIKE子句中指的是任意一个字符，所以需要把'_'下画线进行转义，转义字符设置为'\'。