user: Question: Which Election had 2nd Member George Alexander Morrison, a 1st Party of Unionist, and 3rd Member of John Buchan?
Columns: ['Election', '1st Member', '1st Party', '2nd Member', '2nd Party', '3rd Member', '3rd Party']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1918', 'Sir William Cheyne', 'Coalition Conservative', 'Dugald McCoig Cowan', 'Coalition Liberal', 'Sir Henry Craik', 'Coalition Conservative']
SQL:

assistant: SELECT "Election" FROM "Table" WHERE "2nd Member" = 'George Alexander Morrison' AND "1st Party" = 'Unionist' AND "3rd Member" = 'John Buchan';