quiz -09/04/24

In SQL, what is the purpose of the WHERE clause?

• To sort the results

• To filter the results based on a condition

• To join multiple tables

• To group the results

PL/SQL Variable needs to be declared in the –

• 1. Declaration Section

• 1. Variable Section

• 1. Initialization Section

• 1. None of the above

What is the difference between the DROP and TRUNCATE commands in SQL?

• DROP deletes the table, TRUNCATE deletes only the table data

• TRUNCATE deletes the table, DROP deletes only the table data

• No difference

• Both commands modify table data

What is the purpose of the HAVING clause in SQL, and when would you use it?

• To filter results based on a condition

• To specify conditions on grouped data using aggregate functions

• To sort results in descending order

• To join multiple tables

Explain the difference between a view and a table in SQL.

• Views and tables are identical in SQL

• A view is a virtual table based on the result of a SELECT query, while a table stores actual data

• A view and a table both store actual data

• A view is a subset of a table and cannot be queried independently

Explain the difference between the INNER JOIN and CROSS JOIN in SQL.

• INNER JOIN and CROSS JOIN are synonymous

• INNER JOIN returns only matching rows, while CROSS JOIN returns the Cartesian product of the two tables

• INNER JOIN and CROSS JOIN are not supported in SQL

• INNER JOIN returns the Cartesian product of the two tables, while CROSS JOIN returns only matching rows

Identify the error in
"UPDATE Employees SET Salary = Salary * 1.05 WHERE;"

• UPDATE keyword

• SET keyword

• WHERE clause

• No error

In the query "SELECT Name FROM Employees WHERE Age > 30 AND Department = 'HR';",
what needs to be corrected?

• All Correct

• The SELECT keyword

• The WHERE clause

• The AND operator

Identify the error in
"UPDATE Employees SET Salary = Salary * 1.05 WHERE;"

• UPDATE keyword

• SET keyword

• WHERE clause

• No error

Correct the syntax error in
"DELETE FROM Employees HAVING Age < 25;"

• DELETE keyword

• FROM keyword

• HAVING keyword

• No syntax error