user: Question: Who was the first person elected from Democratic gain?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['California 1', 'Vacant', 'Vacant', 'Vacant', 'Democratic gain']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "Result" = 'Democratic gain';