Advanced Queries

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#1. What does the SQL statement SELECT DISTINCT do?

Deletes duplicate rows

Selects duplicate rows

Selects unique rows

Selects all rows

#2. What is the purpose of the HAVING clause in SQL?

Limit the number of rows

Sort the results

Filter rows before aggregation

Filter groups after aggregation

#3. Which SQL function is used to calculate the total sum of a column?

SUM()

AVG()

COUNT()

TOTAL()

#4. Which SQL keyword is used to join tables based on a condition?

UNION

MERGE

JOIN

WHERE

#5. What does the GROUP BY clause do in SQL?

Deletes rows

Sorts rows

Joins multiple tables

Groups rows for aggregation

#6. Which of the following is used to retrieve data from multiple tables in a single query?

JOIN

UNION

Subquery

All of the above

#7. What is the purpose of the ORDER BY clause?

To group rows

To filter rows

To sort rows

To join rows

#8. Which SQL function returns the number of rows in a table?

NUMBER()

SUM()

ROW_COUNT()

COUNT()

#9. What is a correlated subquery?

A query used in HAVING

A query that runs independently

A query that refers to its outer query

A query used for joins

#10. What does the LIKE operator do in SQL?

Compares exact values

Sorts the data

Matches a pattern in a string

Filters duplicate rows

#11. Which clause is used to combine rows from two or more tables based on a condition?

INTERSECT

WHERE

JOIN

UNION

#12. Which statement best describes UNION in SQL?

Combines data with duplicates

Combines rows from different tables into one result

Deletes rows from a table

Combines data without duplicates

#13. What does OFFSET do in a SQL query?

Orders the rows

Deletes rows

Limits the number of rows

Skips a specified number of rows

#14. What is the purpose of a WITH clause in SQL?

Create a temporary result set

Perform aggregation

Filter rows

Delete rows

#15. What type of JOIN includes unmatched rows from both tables?

OUTER JOIN

CROSS JOIN

SELF JOIN

INNER JOIN

#16. Which of the following is true about NULL values in SQL?

They represent missing or undefined values

They can be compared directly with =

They are equal to empty strings

They do not affect aggregates

#17. Which operator is used to combine the result sets of two queries without duplicates?

UNION

EXCEPT

UNION ALL

INTERSECT

#18. What does the TRUNCATE statement do in SQL?

Deletes all rows and resets the table

Resets the database

Deletes specific rows

Drops the table schema

#19. Which clause is used to rename a column in the result set?

RENAME

ALIAS

LABEL

#20. What is the result of SELECT 2/0; in SQL?

Infinity is returned

An error is returned

0 is returned

NULL is returned

#21. Which SQL statement is used to create a stored procedure?

CREATE QUERY

CREATE FUNCTION

CREATE PROCEDURE

CREATE METHOD

#22. How do you retrieve only the top 5 rows from a result set in SQL?

SELECT TOP 5

FETCH FIRST 5 ROWS ONLY

LIMIT 5

All of the above

#23. What does the RANK() function do in SQL?

Returns the row number of each row

Assigns a rank to rows without gaps

Groups rows for aggregation

Assigns a rank to rows with gaps for ties

#24. What is a CTE (Common Table Expression) in SQL?

A subquery defined with a WITH clause

A permanent table

A temporary table stored in memory

A schema for organizing tables

#25. What does the PARTITION BY clause do in SQL?

Filters duplicate rows

Divides result sets for ranking functions

Joins multiple tables

Groups rows for aggregation

#26. Which aggregate function is used to calculate the average value of a numeric column?

SUM()

AVG()

COUNT()

MEDIAN()

#27. What type of join includes all rows from the left table, even if there are no matches in the right table?

FULL JOIN

LEFT JOIN

CROSS JOIN

INNER JOIN

#28. What does the EXPLAIN statement do in SQL?

Deletes unwanted rows

Analyzes and describes the execution plan of a query

Debugs a query

Provides metadata about a table

#29. Which function is used to concatenate strings in SQL?

JOIN()

ADD()

CONCAT()

MERGE()

#30. What does the CASE statement do in SQL?

Handles conditional logic in queries

Creates temporary tables

Joins multiple tables

Sorts rows alphabetically

#31. Which keyword is used to remove duplicate rows from a query’s result set?

DELETE

FILTER

UNIQUE

DISTINCT

#32. What is the result of this query? SELECT 5 + NULL;

Error

NULL

#33. How do you calculate the number of rows affected by a query?

AFFECTED_ROWS()

ROWS_AFFECTED()

ROW_COUNT()

COUNT(*)

#34. Which SQL function can be used to extract the year from a date column?

PART_YEAR()

EXTRACT_YEAR()

YEAR()

DATEPART()

#35. What is a SELF JOIN in SQL?

A temporary join in memory

A table is joined with all its foreign keys

A table is joined with itself

A subquery-based join

#36. Which of the following clauses can only be used with GROUP BY?

WHERE

HAVING

LIMIT

ORDER BY

#37. What does the LIMIT clause do in SQL?

Sets a maximum value for a column

Limits query execution time

Limits the number of rows returned

Filters duplicate rows

#38. Which operator checks for the presence of a value in a list?

EXISTS

MATCH

#39. What does the MOD() function return in SQL?

A modularized column

The quotient of division

A modified result

The remainder of division

#40. What is the main use of the CHECK constraint in SQL?

To prevent duplicate rows

To set a default value for a column

To ensure a column’s values satisfy a specific condition

To enforce foreign key relationships

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Advanced Queries

There are Multiple Choice Questions

#1. What does the SQL statement SELECT DISTINCT do?

#2. What is the purpose of the HAVING clause in SQL?

#3. Which SQL function is used to calculate the total sum of a column?

#4. Which SQL keyword is used to join tables based on a condition?

#5. What does the GROUP BY clause do in SQL?

#6. Which of the following is used to retrieve data from multiple tables in a single query?

#7. What is the purpose of the ORDER BY clause?

#8. Which SQL function returns the number of rows in a table?

#9. What is a correlated subquery?

#10. What does the LIKE operator do in SQL?

#11. Which clause is used to combine rows from two or more tables based on a condition?

#12. Which statement best describes UNION in SQL?

#13. What does OFFSET do in a SQL query?

#14. What is the purpose of a WITH clause in SQL?

#15. What type of JOIN includes unmatched rows from both tables?

#16. Which of the following is true about NULL values in SQL?

#17. Which operator is used to combine the result sets of two queries without duplicates?

#18. What does the TRUNCATE statement do in SQL?

#19. Which clause is used to rename a column in the result set?

#20. What is the result of SELECT 2/0; in SQL?

#21. Which SQL statement is used to create a stored procedure?

#22. How do you retrieve only the top 5 rows from a result set in SQL?

#23. What does the RANK() function do in SQL?

#24. What is a CTE (Common Table Expression) in SQL?

#25. What does the PARTITION BY clause do in SQL?

#26. Which aggregate function is used to calculate the average value of a numeric column?

#27. What type of join includes all rows from the left table, even if there are no matches in the right table?

#28. What does the EXPLAIN statement do in SQL?

#29. Which function is used to concatenate strings in SQL?

#30. What does the CASE statement do in SQL?

#31. Which keyword is used to remove duplicate rows from a query’s result set?

#32. What is the result of this query? SELECT 5 + NULL;

#33. How do you calculate the number of rows affected by a query?

#34. Which SQL function can be used to extract the year from a date column?

#35. What is a SELF JOIN in SQL?

#36. Which of the following clauses can only be used with GROUP BY?

#37. What does the LIMIT clause do in SQL?

#38. Which operator checks for the presence of a value in a list?

#39. What does the MOD() function return in SQL?

#40. What is the main use of the CHECK constraint in SQL?

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