Table: fa_cup_ties_4
Columns: tie_no
home_team
score
away_team
date

Question: On what Date is Tie no 19?
SQL: SELECT "date" FROM fa_cup_ties_4 WHERE "tie_no" = '19'

Question: What is the Ti no of the Walsall Home game?
SQL: SELECT "tie_no" FROM fa_cup_ties_4 WHERE "home_team" = 'walsall'

Question: What is the Date of Tie no 21?
SQL: SELECT "date" FROM fa_cup_ties_4 WHERE "tie_no" = '21'