VB.Net 连接

Question

我正在慢慢过渡到 VB.Net，看起来最简单的事情完全不同了。我正在尝试连接到 SQL 服务器并获取一些数据。我测试了连接，没问题。现在我试图简单地 select 来自服务器的一些数据并在 Msgbox 中显示名字（或与此相关的任何内容）。这是我到目前为止得到的代码....

Imports System.Data
Imports System.Data.SqlClient

Public Class Form1
    Public conn As New SqlConnection("data source=Tuys1;initial catalog=DDDBuyer; user ID=userID; password=password")
    Private dA As New SqlDataAdapter("Select FirstName, LastName from tblBuyers where Buyerid=1473", conn)
    Private dS As New DataSet
End Class

我不太确定如何从这里开始......我知道有类似

.hasRows

if ds.hasrows then
   msgbox = "HELLO"
End if

或类似在 txtFirstName 中显示 FirstName 的东西

我想了解它是如何工作的，经过一些研究后很难找到一个具体的例子来帮助我完成我想要完成的事情。

Answer 1

Dim custAdapter As SqlDataAdapter = New SqlDataAdapter( _
  "SELECT * FROM dbo.Customers", customerConnection)

Dim ordAdapter As OleDbDataAdapter = New OleDbDataAdapter( _
  "SELECT * FROM Orders", orderConnection)

Dim customerOrders As DataSet = New DataSet()
custAdapter.Fill(customerOrders, "Customers")
ordAdapter.Fill(customerOrders, "Orders")

Dim relation As DataRelation = _
  customerOrders.Relations.Add("CustOrders", _
  customerOrders.Tables("Customers").Columns("CustomerID"), _ 
  customerOrders.Tables("Orders").Columns("CustomerID"))

Dim pRow, cRow As DataRow
For Each pRow In customerOrders.Tables("Customers").Rows
  Console.WriteLine(pRow("CustomerID").ToString())

  For Each cRow In pRow.GetChildRows(relation)
    Console.WriteLine(vbTab & cRow("OrderID").ToString())
  Next
Next

As explained here

VB.Net 连接

VB.Net connection

vb.net

sql-server

database-connection