user: Question: Position of defensive back, and an Overall smaller than 69 is what lowest pick #?
Columns: ['Round', 'Pick #', 'Overall', 'Name', 'Position', 'College']
Types: ['real', 'real', 'real', 'text', 'text', 'text']
Sample row: [2.0, 13.0, 40.0, 'Shane Curry', 'Defensive End', 'Miami (FL)']
SQL:

assistant: SELECT MIN("Pick #") FROM "Table" WHERE "Position" = 'defensive back' AND "Overall" < 69.0;