user: Question: What was the tie no when Wrexham was the away team?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Chesterfield', '2–0', 'Barnsley', '9 December 1967']
SQL:

assistant: SELECT "Tie no" FROM "Table" WHERE "Away team" = 'Wrexham';