Question 1

WHERE with equality

Accepted Answer

WHERE dept = 'Sales' keeps only rows where dept equals the string 'Sales'. Alice (row 1) and Carol (row 3) both match. Bob's dept is 'Eng', so he is excluded.

Question 2

WHERE with !=

Accepted Answer

!= excludes rows where the column equals the given value. Only Gadget has category 'software'. You can also write <> instead of != - both mean not equal in SQL.

Question 3

IN operator

Accepted Answer

IN checks whether the column value matches any value in the list. IN ('shipped', 'delivered') is shorthand for status = 'shipped' OR status = 'delivered'. Rows 2 and 3 match; rows 1 and 4 do not.

Question 4

WHERE with AND

Accepted Answer

AND requires both conditions to be true. Alice is in Sales but her salary (70000) fails the second condition. Carol earns over 80000 but is not in Sales. Only Bob satisfies both.

Question 5

WHERE with OR

Accepted Answer

OR returns a row if at least one condition is true. Alice matches the first condition, Bob matches the second. Carol matches neither and is excluded.