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OCA Oracle Database 11g: SQL Fundamentals I: A Real-World Certification Guide by Steve Ries

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Test your knowledge

  1. Which of the following is NOT a type of subquery?

    a. Single-row

    b. Multi-row

    c. Multi-column

    d. Multi-scalar

  2. What is the output of the following query?
    SELECT blog_url, min(hit_count)
    FROM blog;
      

    a. 123

    b. 18

    c. 0

    d. A "not a single-group function" error is returned.

  3. What is the outcome of the following statement?
    SELECT blog_url, hit_count
    FROM blog
    WHERE hit_count =
      (SELECT blog_url, max(hit_count)
      FROM blog
      GROUP BY blog_url);
      

    a. An error is returned because too many columns are selected in the outer query.

    b. An error is returned because too many columns are selected in the inner query

    c. The statement returns multiple values

    d. The statement returns a single value

  4. Which of the following can be used to create a derived column?

    a. A scalar ...

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