Which comparison operator means 'not equal to' in SQL?
!=
=
<
<>
How would you sort results in descending order by the 'date_created' column?
SORT BY date_created ASC
ORDER BY date_created ASC
ORDER BY date_created DESC
SORT BY date_created DESC
In a SQL query, what does the logical operator 'AND' do?
It sorts the results in descending order.
It negates a condition.
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.
By default, how does the 'ORDER BY' clause sort data?
Alphabetically
In ascending order
In descending order
Randomly
What is the result of SELECT NOW(); in SQL?
SELECT NOW();
Current date
Current date and time
Current time
An error message
Which keyword is used in conjunction with the UPDATE statement to specify the conditions for updating rows?
WHERE
CONDITION
WHEN
IF
What potential issue should be considered when using correlated subqueries?
They can lead to performance issues if not used carefully.
They require the use of the JOIN clause.
They cannot return more than one column.
They cannot be used with aggregate functions.
What type of join returns all rows from the left table, even if there are no matching rows in the right table?
INNER JOIN
FULL JOIN
LEFT JOIN
RIGHT JOIN
Which type of subquery is used to check if a value exists in a list of values returned by another query?
IN Subquery
Correlated Subquery
Nested Subquery
EXISTS Subquery
What is the purpose of the 'LIMIT' clause in SQL?
It filters rows based on a condition.
It groups rows with the same values.
It restricts the number of rows returned by the query.
It sorts the result set.