Oracle SQL Functions and Subqueries Quiz

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4. Which function returns the current date and time in Oracle SQL?

TODAY()

NOW()

SYSDATE

CURRENT_DATE()

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6. In Oracle SQL, which function concatenates two strings?

APPEND()

CONCAT()

JOIN()

MERGE()

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8. What does the LENGTH function return in Oracle SQL?

Number of characters in a string

Number of words in a string

Size of a table in bytes

Number of columns in a table

9. Which operator is used with multi-row subqueries to check if a value matches any row?

=

ANY

>

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11. What is the difference between a single-row subquery and a multi-row subquery?

Single-row uses WHERE; multi-row uses HAVING

Single-row returns one row; multi-row returns multiple rows

Single-row is faster than multi-row

Multi-row subqueries cannot use aggregate functions

12. Which function returns the number of rows that match a specified criteria in Oracle SQL?

COUNT()

SUM()

AVG()

MAX()

13. Which aggregate function returns the highest value in Oracle SQL?

HIGHEST()

MAXIMUM()

MAX()

TOP()

14. In Oracle, the IN operator is often used with subqueries. What does it check?

If a value equals any value returned by the subquery

If a value is greater than the subquery result

If a value exists in multiple tables

If two subqueries return identical results

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16. Which subquery type can return multiple rows and columns?

Scalar subquery

Inline view

Single-row subquery

Correlated subquery

17. What does the NVL function do in Oracle SQL?

Converts NULL values to a specified value

Removes duplicate rows

Calculates the average of values

Rounds numbers to nearest integer

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19. Which clause is used with GROUP BY to filter aggregated results in Oracle SQL?

WHERE

HAVING

FILTER

ON

20. The SUBSTR function in Oracle extracts a substring. What does SUBSTR('DATABASE', 1, 4) return?

ATAS

DATA

DATABASEE

DBASE

21. What is the purpose of a correlated subquery in Oracle SQL?

Join multiple tables without using JOIN syntax

Reference columns from the outer query within the subquery

Improve performance of INSERT statements

Replace aggregate functions

Oracle SQL Associate Functions and Subqueries Quiz

1. A subquery in the FROM clause of an Oracle SELECT statement is called a____.

2.

What first name or nickname would you like us to use?

2. A subquery that references a column from the outer query is called a____subquery.

3. When using GROUP BY with aggregate functions, non-aggregated columns must be____.

4. Which function returns the current date and time in Oracle SQL?

5. A NOT IN subquery will exclude rows where the value matches any result from the____.

6. In Oracle SQL, which function concatenates two strings?

7. The EXISTS operator with a subquery checks if the subquery____.

8. What does the LENGTH function return in Oracle SQL?

9. Which operator is used with multi-row subqueries to check if a value matches any row?

10. The ROUND function in Oracle SQL rounds a number. ROUND(123.456, 2) returns____.

11. What is the difference between a single-row subquery and a multi-row subquery?

12. Which function returns the number of rows that match a specified criteria in Oracle SQL?

13. Which aggregate function returns the highest value in Oracle SQL?

14. In Oracle, the IN operator is often used with subqueries. What does it check?

15. The UPPER function in Oracle SQL____.

16. Which subquery type can return multiple rows and columns?

17. What does the NVL function do in Oracle SQL?

18. A scalar subquery returns____.

19. Which clause is used with GROUP BY to filter aggregated results in Oracle SQL?

20. The SUBSTR function in Oracle extracts a substring. What does SUBSTR('DATABASE', 1, 4) return?

21. What is the purpose of a correlated subquery in Oracle SQL?