user: Question: What is the number when against is Rajasthan Royals?
Columns: ['No.', 'Season', 'Bowler', 'Batsmen', 'For', 'Against', 'Ground', 'Scorecard']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 2008.0, 'Lakshmipathy Balaji', 'Irfan Pathan Piyush Chawla VRV Singh', 'Chennai Super Kings', 'Kings XI Punjab', 'Chennai – MA Chidambaram Stadium', '10 May 2008']
SQL:

assistant: SELECT "No." FROM "Table" WHERE "Against" = 'Rajasthan Royals';