Question

我有2个表，我想从单个查询中获取数据集以在图表中显示它。但我在执行中遇到错误。只有年份和expYear以及Month和Exp Month这些列可能具有共同数据。每一行都有其年份和月份字段。

这是我正在尝试的查询：

select 
  t.transExpense
  g.grocExpense
from
  (Select sum(traexpense) as transExpense from 
              transportExpense where Year="2014") t,
  (Select sum(groexpense) as grocExpense from 
              groceryExpense where expYear="2014") g

请帮忙。

Answer 1

在所选字段之间添加逗号：

select 
t.transExpense,  -- << right there
g.grocExpense
from
(Select sum(traexpense) as transExpense from transportExpense where Year="2014") t,
(Select sum(groexpense) as grocExpense from groceryExpense where expYear="2014") g

Answer 2

您在t.transExpense之后缺少逗号。

但是，要返回单个值，您不需要将子查询放入FROM子句中;您可以在SELECT中直接使用它们作为标量子查询：

SELECT (SELECT SUM(traexpense)
        FROM transportExpense
        WHERE Year = '2014'
       ) AS transExpense,
       (SELECT SUM(groexpense)
        FROM grocExpense
        WHERE expYear = '2014'
       ) AS grocExpense;

Answer 3

可以使用JOIN Query解决。类似的东西：

SELECT  sum(t.traexpense) as t.transExpense,  sum(g.groexpense) as g.grocExpense
from transportExpense t LEFT JOIN groceryExpense g ON t.fieldname=g.fieldname
where g.expYear=2014 and t. Year=2014

如果您的牌桌没有任何加入的公共字段，您可以使用t.Year和g.expYear加入。

单个选择查询中两个不同表上的求和函数

3 个答案: