Question

我有一个包含3列REF Handle Size Price 2002 t-shirt1 M 23 2003 t-shirt1 L 23 3001 t-shirt2 S 24 3002 t-shirt2 M 24 3003 t-shirt2 L 24，source，dest的表格，其值为

total cost

我想要总成本

Agra Delhi 500
Agra Kanpur 400
Delhi Agra 900
Kanpur Agra 500

Answer 1

您可以使用LEAST（）和GREATEST（）函数以及GROUP BY查询：

SELECT
  LEAST(source, dest),
  GREATEST(source, dest),
  SUM(total_cost)
FROM
  tablename
GROUP BY
  LEAST(source, dest),
  GREATEST(source, dest)

Answer 2

SELECT a.source, a.dest, (a.total_cost + b.total_cost) round_trip_cost
FROM my_tab as a 
    LEFT OUTER JOIN my_tab as b 
    ON (a.source = b.dest AND b.source = a.dest)

寻找道路的总成本

2 个答案: