我见过很多有模棱两可的问题的案例，试过很多东西，还是不行

Question

我想知道，为什么在这种情况下，它一直说Quantity column is ambiguous，有人可以帮忙吗？

SELECT SUM(AmountPaid),SUM(Quantity), ice_cream.IceCream
FROM ice_cream 
INNER JOIN ice_cream_ingredient ON (ice_cream.IceCreamID =
ice_cream_ingredient.fkIceCreamID)
INNER JOIN ingredients ON (ice_cream_ingredient.fkIngredientID =
ingredients.IngredientID)
INNER JOIN sales ON (sales.fkIceCreamID =
ice_cream.IceCreamID)
WHERE IceCream='Vanilla Dream'

Answer 1

当查询中有多个 table 时，您应该始终限定列名称。另外，学会使用table别名。

不清楚正确的限定名称是什么。这是一个猜测：

SELECT SUM(s.AmountPaid), SUM(s.Quantity), ic.IceCream
FROM ice_cream ic INNER JOIN
     ice_cream_ingredient ici
     ON ic.IceCreamID = ici.fkIceCreamID INNER JOIN
     ingredients i
     ON ici.fkIngredientID = i.IngredientID INNER JOIN
     sales s
     ON s.fkIceCreamID = ic.IceCreamID
WHERE ic.IceCream = 'Vanilla Dream';

我见过很多有模棱两可的问题的案例，试过很多东西，还是不行

I have seen many cases with ambiguous problems and tried many stuff, still does not work

mysql

sql

ambiguous