What will be the result of the following MySQL command?

WHERE end_date IS NULL 
AND (title=’teller’ OR start_date < ‘2007-01-01’)

Solution (By Examveda Team)

This MySQL command is used to filter rows from a table based on conditions related to "end_date", "title", and "start_date". Let's break down the command:
* WHERE end_date IS NULL: This part selects rows where the "end_date" column is NULL. It means that the value in the "end_date" column is empty or unknown.
* AND (title=’teller’ OR start_date < ‘2007-01-01’): This part uses the AND operator to combine two conditions. Let's further break down this part: * title=’teller’: This condition selects rows where the "title" column is equal to 'teller'. * OR start_date < ‘2007-01-01’: This condition selects rows where the "start_date" column is before '2007-01-01'.
In summary, the command will select rows that meet both conditions:
* The "end_date" must be NULL. * Either the "title" is 'teller', OR the "start_date" is before '2007-01-01'.
Therefore, the correct answer is Option D: All of the mentioned.
The command will select rows that meet any of these criteria:
* Employees with a NULL "end_date" and the title 'teller'. * Employees with a NULL "end_date" and a start date before '2007-01-01'.