mysql - 结果表mysql中两行的总和

Question

我想从结果查询中获取两行的总和。我已经尝试过这段代码，但它似乎不起作用。但如果我删除 tot，它会起作用，但不会给出总数。

INSERT INTO totaltransportcost
    select year(date) as y, month(date) as m, sum(FuelCost) as fc, SUM(OtherExpenses) as oe, SUM(fc+as) as tot
    from turn
    group by year(date), month(date)

Answer 1

一个问题(至少)是您无法在定义别名的同一个 SELECT 中重复使用别名。所以:

INSERT INTO totaltransportcost
    select year(date) as y, month(date) as m, sum(FuelCost) as fc, 
           SUM(OtherExpenses) as oe,
           SUM(FuelCost + OtherExpenses) as tot
    from turn
    group by year(date), month(date);

我还建议您包含所有正在插入的列。这是一个值得养成的好习惯。所以:

insert into totaltransportcost(y, m, fc, oe, tot)  -- or whatever the column names are
     . . .