C# 从两个表中进行选择，并对其中一个列和group by itemkey中的值求和

我只是在寻求帮助，因为我一直在寻找如何解决c mysql代码。我有两个表，一个用于股票上市，另一个用于监控销售

SELECT 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice, 
    sales.ItemKey, 
    SUM(sales.QuantitySales) As Qsales 
FROM 
    sales 
    INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey 
WHERE 
    sales.dateSales BETWEEN '2019/11/12' AND '2019/11/18'
GROUP BY 
    sales.ItemKey, 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice

库存表

销售表

数据网格视图上显示了什么

    | ItemKey    | Qtn | Product Name | Buying Price| Selling Price
    ----------------------------------------------------
    | 1572661229 | 25   |  blue band   | 20          | 30
    | 1572661899 | 35   |  salt        | 10          | 20
    | 1572661234 | 20   |  sugar       | 80          | 100
    | 1572664312 | 60   |  maize flour | 100         | 150
------------------------------------------------------------
    | TOTAL      | 140  |

我希望在datagridview上显示的内容

    | ItemKey    | Qtn | Product Name | Buying Price| Selling Price
    ----------------------------------------------------
    | 1572661229 | 5   |  blue band   | 20          | 30
    | 1572661899 | 7   |  salt        | 10          | 20
    | 1572661234 | 4   |  sugar       | 80          | 100
    | 1572664312 | 12  |  maize flour | 100         | 150
------------------------------------------------------------
    | TOTAL      | 28  |

该代码在单个日期运行良好，但当我检索整个销售期间的数据时，检索到的数据已乘以某个系数。请帮我解决上面的代码

完整代码

public void getSalesData(String date, DataGridView listV, String Seller, String[] SalesPeriod)
    {
        SqlCommand cmd;
        SqlDataAdapter adapter;
        DataTable dt = new DataTable();
        listV.Rows.Clear();
        int bpTotal = 0;
        int spTotal = 0;
        int profit = 0;
        int i = 0;
        int qtnFinalTotal = 0;
        int bpFinalTotal = 0;
        int spFinalTotal = 0;
        int finalProfit = 0;
        String sql;

        if(string.Equals(Seller, "10")){
            sql = "SELECT inventory.Item, inventory.buyingPrice, inventory.sellingPrice, sales.ItemKey, SUM(sales.QuantitySales) As Qsales FROM sales INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey WHERE sales.dateSales BETWEEN '" + SalesPeriod[0] + "' AND '" + SalesPeriod[1] + "' GROUP BY sales.ItemKey, inventory.Item, inventory.buyingPrice, inventory.sellingPrice";
            //sql = "SELECT MAX(inventory.Item) As Product, inventory.buyingPrice, inventory.sellingPrice, sales.ItemKey, SUM(sales.QuantitySales) As Qsales FROM sales INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey WHERE sales.dateSales BETWEEN '" + SalesPeriod[0] + "' AND '" + SalesPeriod[1] + "' GROUP BY sales.ItemKey, inventory.buyingPrice, inventory.sellingPrice";
        }
        else
        {
            sql = "SELECT inventory.Item, inventory.buyingPrice, inventory.sellingPrice, sales.ItemKey, SUM(sales.QuantitySales) As Qsales FROM sales INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey WHERE sales.dateSales BETWEEN '" + SalesPeriod[0] + "' AND '" + SalesPeriod[1] + "' AND inventory.date BETWEEN '" + SalesPeriod[0] + "' AND '" + SalesPeriod[1] + "' AND Sales.SellerId='" + Seller + "' GROUP BY sales.ItemKey, inventory.Item, inventory.buyingPrice, inventory.sellingPrice";
        }

        cmd = new SqlCommand(sql, con);

        try
        {
            con.Open();

            adapter = new SqlDataAdapter(cmd);
            adapter.Fill(dt);

            foreach (DataRow col in dt.Rows)
            {
                int n = listV.Rows.Add();
                i++;

                listV.Rows[n].Cells[0].Value = col["ItemKey"].ToString();
                listV.Rows[n].Cells[1].Value = col["Item"].ToString();
                listV.Rows[n].Cells[2].Value = col["Qsales"].ToString();
                listV.Rows[n].Cells[3].Value = col["buyingPrice"].ToString();

                bpTotal = Convert.ToInt32(col["buyingPrice"]) * Convert.ToInt32(col["Qsales"]);
                listV.Rows[n].Cells[4].Value = bpTotal.ToString();

                listV.Rows[n].Cells[5].Value = col["sellingPrice"].ToString();

                spTotal =Convert.ToInt32(col["sellingPrice"]) * Convert.ToInt32(col["Qsales"]);
                listV.Rows[n].Cells[6].Value = spTotal.ToString();

                profit = spTotal - bpTotal;

                listV.Rows[n].Cells[7].Value = profit.ToString();

                qtnFinalTotal = qtnFinalTotal + Convert.ToInt32(col["Qsales"]);
                bpFinalTotal = bpFinalTotal + bpTotal;
                spFinalTotal = spFinalTotal + spTotal;
                finalProfit = spFinalTotal - bpFinalTotal;
            }

            listV.Rows[i].Cells[1].Value = "TOTAL";
            listV.Rows[i].Cells[2].Value = qtnFinalTotal.ToString();
            listV.Rows[i].Cells[4].Value = bpFinalTotal.ToString();
            listV.Rows[i].Cells[6].Value = spFinalTotal.ToString();
            listV.Rows[i].Cells[7].Value = finalProfit.ToString();

            dt.Rows.Clear();

            //Add Styling
            listV.Rows[i].DefaultCellStyle.BackColor = Color.Beige;
            listV.Rows[i].DefaultCellStyle.Font = new Font("Tahoma", 9, FontStyle.Bold);
            dt.Rows.Clear();

            con.Close();

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
            con.Close();
        }
    }

---

谢谢你们试着回答我的问题。最后我得到了答案。我在stock表中添加了一个新的日期列，然后添加了下面的行

AND sales.dateSales = inventory.date

从此改变

SELECT 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice, 
    sales.ItemKey, 
    SUM(sales.QuantitySales) As Qsales 
FROM 
    sales 
    INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey 
WHERE 
    sales.dateSales BETWEEN '2019/11/12' AND '2019/11/18'
GROUP BY 
    sales.ItemKey, 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice

对此

    SELECT 
        inventory.Item, 
        inventory.buyingPrice, 
        inventory.sellingPrice, 
        sales.ItemKey, 
        SUM(sales.QuantitySales) As Qsales 
    FROM 
        sales 
        INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey 
    WHERE 
        sales.dateSales BETWEEN '2019/11/12' AND '2019/11/18' AND sales.dateSales = inventory.date
    GROUP BY 
        sales.ItemKey, 
        inventory.Item, 
        inventory.buyingPrice,
        inventory.sellingPrice

---

它工作得很好

工作得很好，你能给我们更多的细节吗？否则它看起来很好谢谢你的回复，我已经看过你的答案了，非常棒，但是你离开了dateSales seletionI刚刚被困的地方，因为它仍然返回相同的数据和乘数。。检查editHi D Shih，你的代码运行良好，但是当我使用c时，他们的行为有些不端

SELECT 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice, 
    sales.ItemKey, 
    SUM(sales.QuantitySales) As Qsales 
FROM 
    sales 
    INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey 
WHERE 
    sales.dateSales BETWEEN '2019/11/12' AND '2019/11/18'
GROUP BY 
    sales.ItemKey, 
    inventory.Item, 
    inventory.buyingPrice, 
    inventory.sellingPrice

    SELECT 
        inventory.Item, 
        inventory.buyingPrice, 
        inventory.sellingPrice, 
        sales.ItemKey, 
        SUM(sales.QuantitySales) As Qsales 
    FROM 
        sales 
        INNER JOIN inventory ON sales.ItemKey=inventory.ItemKey 
    WHERE 
        sales.dateSales BETWEEN '2019/11/12' AND '2019/11/18' AND sales.dateSales = inventory.date
    GROUP BY 
        sales.ItemKey, 
        inventory.Item, 
        inventory.buyingPrice,
        inventory.sellingPrice