C# 选择事务，仅显示一行，但数据库中有多行

在此空白处，我选择了交易。示例在PONo为17的数据库中有3行，我只想在列表视图中显示一行。可能吗

void GetSupply()
{
    con.Open();
    SqlCommand cmd = new SqlCommand();
    cmd.Connection = con;
    cmd.CommandText = "SELECT Supplier.SupplierName, PurchaseOrder.PONo, PurchaseOrder.PODate, " +
        "PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate, PurchaseOrder.POPaymentMethod, " +
        "PurchaseOrder.POReceiptNo, PurchaseOrderDetails.POAmount, PurchaseOrder.POPaymentDate, " +
        "PurchaseOrder.POStatus FROM PurchaseOrder INNER JOIN PurchaseOrderDetails " +
        "ON PurchaseOrder.PONo = PurchaseOrderDetails.PONo INNER JOIN Supplier ON " +
        "PurchaseOrder.SupplierNo = Supplier.SupplierID " +
        "ORDER BY PurchaseOrder.PODate DESC";
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    da.Fill(ds, "PurchaseOrderDetails");
    lvPO.DataSource = ds;
    lvPO.DataBind();
    con.Close();
}

现在看起来是这样的

我想这样表现出来

---

您可以尝试使用

选择DISTINCT

ie

cmd.CommandText = "SELECT DISTINCT Supplier.SupplierName, PurchaseOrder.PONo, PurchaseOrder.PODate, " +
        "PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate, " +
        "FROM PurchaseOrder INNER JOIN PurchaseOrderDetails " +
        "ON PurchaseOrder.PONo = PurchaseOrderDetails.PONo INNER JOIN Supplier ON " +
        "PurchaseOrder.SupplierNo = Supplier.SupplierID " +
        "ORDER BY PurchaseOrder.PODate DESC";

或者尝试使用分组方式

cmd.CommandText = "SELECT Supplier.SupplierName, PurchaseOrder.PONo, PurchaseOrder.PODate, " +
        "PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate, " +
        "FROM PurchaseOrder INNER JOIN PurchaseOrderDetails " +
        "ON PurchaseOrder.PONo = PurchaseOrderDetails.PONo INNER JOIN Supplier ON " +
        "PurchaseOrder.SupplierNo = Supplier.SupplierID " +
        "GROUP BY PurchaseOrder.PONo,Supplier.SupplierName, PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate ORDER BY PurchaseOrder.PODate DESC";

---

您可以尝试使用

select DISTINCT

ie

cmd.CommandText = "SELECT DISTINCT Supplier.SupplierName, PurchaseOrder.PONo, PurchaseOrder.PODate, " +
        "PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate, " +
        "FROM PurchaseOrder INNER JOIN PurchaseOrderDetails " +
        "ON PurchaseOrder.PONo = PurchaseOrderDetails.PONo INNER JOIN Supplier ON " +
        "PurchaseOrder.SupplierNo = Supplier.SupplierID " +
        "ORDER BY PurchaseOrder.PODate DESC";

或者尝试使用分组方式

cmd.CommandText = "SELECT Supplier.SupplierName, PurchaseOrder.PONo, PurchaseOrder.PODate, " +
        "PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate, " +
        "FROM PurchaseOrder INNER JOIN PurchaseOrderDetails " +
        "ON PurchaseOrder.PONo = PurchaseOrderDetails.PONo INNER JOIN Supplier ON " +
        "PurchaseOrder.SupplierNo = Supplier.SupplierID " +
        "GROUP BY PurchaseOrder.PONo,Supplier.SupplierName, PurchaseOrder.PODateReceived, PurchaseOrder.PODeliveryDate ORDER BY PurchaseOrder.PODate DESC";

---

只需在查询中使用distinct

选择distinct….

另一种方法选择Top 1I我不能使用Top 1，因为存在的数量比需要显示的数量少。只需在查询中使用distinct

选择distinct….

另一种方法选择Top 1I不能使用Top 1，因为存在的问题比需要显示的问题要多，所以我如何做出不同的声明？@gamered123:-我已经在我的答案中添加了查询。你可以用它。我已经把它放好了，但它仍然占3rows@gamered123：-尝试使用

SELECT TOP 1 Supplier.SupplierName，PurchaseOrder.PONo，….

TOP 1无法使用，因为我还需要显示不同的交易记录。我只是想说明我是否做了一个不同的陈述？@gamered123:-我已经在我的答案中添加了这个查询。你可以用它。我已经把它放好了，但它仍然占3rows@gamered123：-尝试使用

SELECT TOP 1 Supplier.SupplierName，PurchaseOrder.PONo，….

TOP 1无法使用，因为我还需要显示不同的交易记录。我只是想消除重复