BENTONVILLE, Ark. — Wal-Mart’s Q2 sales and earnings exceeded Wall Street estimates as the retail giant pushed expansion in online sales. Earnings of $1.08 per share squeaked past analyst estimates by a single cent, while total revenues came to $123.36 billion, compared to an expected $122.84 billion. U.S. comparable sales rose 1.8%, led by food sales, with a 1.3% increase in traffic. The company continued to reap the rewards of its acquisition of Jet.com, as e-commerce sales soared by 67% year over year.