Which type of subquery is used to check if a value exists in a list of values returned by another query?
EXISTS Subquery
Nested Subquery
IN Subquery
Correlated Subquery
What does the asterisk (*) symbol represent when used in a SELECT statement?
A wildcard for searching data
A specific column name
A comment indicator
All columns
How would you convert the text 'hello world' to uppercase in SQL?
MAKE_UPPER('hello world')
UPPER('hello world')
UCASE('hello world')
TO_UPPER('hello world')
Which SQL clause is used to sort the result set?
ORDER
ORDER BY
SORT
SORT BY
By default, how does the 'ORDER BY' clause sort data?
Randomly
In descending order
Alphabetically
In ascending order
Which comparison operator means 'not equal to' in SQL?
<>
=
!=
<
What SQL clause is used to group rows with the same value in one or more columns into a summary row?
SELECT
WHERE
GROUP BY
What is the purpose of the 'OR' operator in a SQL WHERE clause?
It limits the number of rows returned.
It negates a condition.
It selects rows where at least one condition is true.
It selects rows where both conditions are true.
In a SQL query, what does the logical operator 'AND' do?
It combines two conditions, and at least one condition must be true for the row to be included.
It combines two conditions, and both conditions must be true for the row to be included.
It sorts the results in descending order.
What type of join returns all rows from both tables, regardless of whether there is a match?
INNER JOIN
LEFT JOIN
RIGHT JOIN
FULL OUTER JOIN