CREATE TABLE table_50845 ("Tie no" CLOB, "Home team" CLOB, "Score" CLOB, "Away team" CLOB, "Date" CLOB)

Who is the home team on 31 January 1951 when away team was Sheffield United?
SELECT "Home team" FROM table_50845 WHERE "Date" = '31 january 1951' AND "Away team" = 'sheffield united'
SELECT "Home team" FROM "table_50845" WHERE "Away team" = 'sheffield united' AND "Date" = '31 january 1951'