Question

在做了sql查询后付出了很多努力我最终陷入了混乱，到目前为止我所做的是这是table1

select bill_no='2016-2017', B_id, COALESCE(sum(amount-gr),0) as amount, COALESCE (sum(tax),0) as tax, COALESCE(sum(amount_paid),0) as amount_paid, COALESCE(sum(gr),0) as gr,'sun4269' as forUser from tbl_addbill 
 where forUser='sun4269' and bill_date between '2016-04-01' and '2017-03-31' group by B_id;

bill_no     B_id     amount tax   amount_paid   gr  forUser
2016-2017   B-1       34875 0       0           0    sun4269
2016-2017   L-1       21014 0     19363         0    sun4269
2016-2017   P-1       10217 0       0           0    sun4269
2016-2017   S-1       30000 0    14000          0    sun4269
2016-2017   T-1       66237 0    21426          0    sun4269

这就是表2

select bill_no,B_id,amount,tax,amount_paid,gr,forUser from tbl_addbill where forUser='sun4269' and bill_date is null and bill_no='2015-2016'       

bill_no     B_id    amount  tax    amount_paid  gr  forUser
2015-2016   K-1     181523  0      22159        0   sun4269
2015-2016   L-1     25266   0      4644         0   sun4269
2015-2016   P-1     122383  0      122383   113162  sun4269
2015-2016   A-1     38367   1827   0            0   sun4269
2015-2016   S-1     698262  18575  577120   113449  sun4269

可以看出，table1和table2中的列'B_id'具有相同和不同的值（L-1重复但B-1不重复），我想要的是如果L-1重复表格，然后金额，amount_paid，tax，gr sum与两个表中的'2016-2017'相加，如果B-1在任何表格中都是唯一的那么它也应该是'2016-2017的价值“

Answer 1

override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) { super.traitCollectionDidChange(previousTraitCollection) let pointSize = UIFontDescriptor.preferredFontDescriptor(withTextStyle: .title1).pointSize titleLabel.font = titleLabel.font.withSize(pointSize) }您的table1和table2查询，并在UNION表格上执行GROUP BY及相关的汇总功能。

如果你只是从table1和table2的UNION开始，你会看到我的意思，因为结果将是一个表，来自table1和table2的所有行;然后，您可以添加UNION和所需的聚合函数（例如GROUP BY B_id）。

Answer 2

不确定您到底在寻找什么，但有些条件聚合会有帮助吗？

 select..., sum(case when bill_date between '2016-04-01' and '2017-03-31'then amount-gr else null end) [2016billdata], 
 sum(case when bill_date between '2015-04-01' and '2016-03-31'then amount-gr else null end) [2015billdata]....from tbl_addbill
 group by...

sql查询根据数据不同的列对2个表的列求和

2 个答案: