Question

我正在尝试运行一个将计算＆＃34; TOTAL COST＆＃34;的查询。我目前的代码是：

SELECT [Main Query].SaltInfo_ID, Sum([Main Query].Tons) AS [Total Of Tons], Sum([Main Query].BlastTons) AS [Total Of BlastTons], Sum([Main Query].LiqGal) AS [Total Of LiqGal], Sum([Main Query].LiqBlastGal) AS [Total Of LiqBlastGal], IIf([Main Query].[EventDate]<#7/31/2016#,((Nz([Total Of Tons],0)+Nz([Total of BlastTons],0))*66.63)+((Nz([Total Of LiqGal],0)+Nz([Total of LiqBlastGal],0))*0.182),((Nz([Total Of Tons],0)+Nz([Total of BlastTons],0))*50.4)+((Nz([Total Of LiqGal],0)+Nz([Total of LiqBlastGal],0))*0.1594)) AS [TOTAL COST]
FROM [Main Query]
WHERE ((([Main Query].EventDate) Is Not Null))
GROUP BY [Main Query].SaltInfo_ID;

这很好用;但是我需要更改计算的[TOTAL COST]以根据[EventDate]计算值。如果活动日期在2016年7月31日之前，则Tons和BlastTons的成本为66.63美元，而LiqGal和LiqBlastGal的成本为0.182美元。 2016年7月31日之后，成本分别变为50.40美元和0.1594美元。你能帮忙正确编码，以便正确计算吗？我试过这个，但它没有用：

using System.Collections.Generic;
using System.Windows.Forms;

namespace FindTheCheckedBoxes
{
    public partial class Form1 : Form
    {
        List<TestObject> list = new List<TestObject>();

        List<int> positionId = new List<int>();

        public Form1()
        {
            InitializeComponent();
            PopulateDataGrid();

            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                if ((bool)row.Cells[0].Value == true)
                    positionId.Add((int)row.Cells[1].Value);
            }

            // sets the window title to the columns found ...
            this.Text = string.Join(", ", positionId);
        }
        void PopulateDataGrid()
        {
            list.Add(new TestObject { tick = false, LineNum = 1 });
            list.Add(new TestObject { tick = true, LineNum = 2 });
            list.Add(new TestObject { tick = false, LineNum = 3 });
            list.Add(new TestObject { tick = true, LineNum = 4 });

            dataGridView1.DataSource = list;
        }
    }
    class TestObject
    {
        public bool tick { get; set; }
        public int LineNum { get; set; }
    }
}

当我尝试运行查询时，我收到错误：＆＃34;您试图执行不包含指定表达式的查询＆lt; IIf（[主要查询]。[EventDate]＆lt;＃ 7/31/2016＃，（（Nz（[总吨数]，0）+ Nz（[BlastTons总数]，0））* 66.63）+（（Nz（[LiqGal总和]，0）+ Nz（ [LiqBlastGal的总和]，0））* 0.182），（（Nz（[总吨数]，0）+ Nz（[BlastTons总数]，0））* 50.4）+（（Nz（[LiqGal的总和] ，0）+ Nz（[总和Li＆＃39;作为聚合函数的一部分。＆＃34;

我做错了什么？任何帮助将不胜感激！

Answer 1

查询不是放置这种逻辑的地方。您需要另一张表来保存您的定价：

create table ProductCosts (Product varchar(255), StartDate datetime, EndDate DateTime, Cost Currency)

insert into ProductCosts(Product, Cost, StartDate,EndDate)
Select 'BlastTons', 66.63, '1/1/1990','7/31/2016'
union select 'LiqGal', 0.182, '1/1/1990','7/31/2016'
union select 'LiqBlastGal', 0.182,'1/1/1990','7/31/2016'
union Select 'BlastTons', 50.40, '8/1/2016','1/1/2050'
union select 'LiqGal', 0.1594, '8/1/2016','1/1/2050'
union select 'LiqBlastGal', 0.1594, '8/1/2016','1/1/2050'

然后你的最终查询可能是这样的：

SELECT [Main Query].SaltInfo_ID, Sum([Main Query].Tons) AS [Total Of Tons]
    , Sum([Main Query].BlastTons) AS [Total Of BlastTons]
    , Sum([Main Query].LiqGal) AS [Total Of LiqGal]
    , Sum([Main Query].LiqBlastGal) AS [Total Of LiqBlastGal]
    , ((Nz([Total Of Tons])+Nz([Total of BlastTons]))*BlastTons.Cost)+((Nz([Total Of LiqGal])*LiqGal.Cost + Nz([Total of LiqBlastGal]))*LiqBlastGal.Cost) AS [TOTAL COST]
FROM [Main Query] mq
inner join ProductCosts BlastTons on BlastTons.StartDate <= mq.[EventDate] and BlastTons.EndDate > mq.[EventDate] and BlastTons.Product = 'BlastTons'
inner join ProductCosts LiqGal on BlastTons.StartDate <= mq.[EventDate] and BlastTons.EndDate > mq.[EventDate] and BlastTons.Product = 'LiqGal'
inner join ProductCosts LiqBlastGal on BlastTons.StartDate <= mq.[EventDate] and BlastTons.EndDate > mq.[EventDate] and BlastTons.Product = 'LiqBlastGal'
WHERE ((([Main Query].EventDate) Is Not Null))
GROUP BY [Main Query].SaltInfo_ID;

理想情况下，每种类型的产品都没有联接，但这会让您首先更改Main Query。

基于日期的访问查询变更计算

1 个答案: