浅谈如何使用vb.net从数据库中提取数据

Imports System.Windows.Forms.Application
Module Module1
 Sub Main()
  'form1 是测试多文档窗口
  'Dim frm1 As New Form1()
  'frm1.Show()
  Dim formStudentSysMain As New FormStudentSysMain()
  formStudentSysMain.Show()
  Do While True
   DoEvents()
  Loop

 End Sub
End Module

Imports System.Data.SqlClient
Public Class FormStudentSysMain
 Public DBConnstr As String = "Data Source=LJJ-FF\\LJJ;Initial Catalog=TestMvc;User ID=sa;Password=111111"
 Private Sub quitMenuItem_Click(sender As Object, e As EventArgs) Handles quitMenuItem.Click
  End
 End Sub

 Private Sub selectinfoMenuItem_Click(sender As Object, e As EventArgs) Handles selectinfoMenuItem.Click
  Dim formSearchStudent As New FormSearchStudent
  formSearchStudent.MdiParent = Me
  formSearchStudent.WindowState = FormWindowState.Normal
  formSearchStudent.Show()
 End Sub

 Private Sub updateinfoMenuItem1_Click(sender As Object, e As EventArgs) Handles updateinfoMenuItem1.Click
  Dim formStudentInfo As New FormStudentInfo
  FormSearchStudent.MdiParent = Me
  FormSearchStudent.WindowState = FormWindowState.Normal
  formStudentInfo.Show()
 End Sub

 Private Sub importscoreMenuItem_Click(sender As Object, e As EventArgs) Handles importscoreMenuItem.Click
  Dim formStudentCourse As New FormStudentCourse
  FormSearchStudent.MdiParent = Me
  FormSearchStudent.WindowState = FormWindowState.Normal
  formStudentCourse.Show()
 End Sub

 Private Sub cascadeMenuItem_Click(sender As Object, e As EventArgs) Handles cascadeMenuItem.Click
  Me.LayoutMdi(MdiLayout.Cascade)
 End Sub

 Private Sub horizonMenuItem_Click(sender As Object, e As EventArgs) Handles horizonMenuItem.Click
  Me.LayoutMdi(MdiLayout.TileHorizontal)
 End Sub

 Private Sub verticalMenuItem_Click(sender As Object, e As EventArgs) Handles verticalMenuItem.Click
  Me.LayoutMdi(MdiLayout.TileVertical)

 End Sub

 Private Sub FormStudentSysMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load

 End Sub
End Class

Imports System.Data.SqlClient
Public Class FormSearchStudent

 Private Sub Label1_Click(sender As Object, e As EventArgs) Handles Label1.Click

 End Sub

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
  Dim sqlConStr As String = My.Forms.FormStudentSysMain.DBConnstr
  Dim sqlStr As String = "select * from student "
  Dim sqlDataAdapter As New SqlDataAdapter
  Dim dataSet As New DataSet
  Dim sqlConnection As New SqlConnection(sqlConStr)
  If Trim(txtName.Text) <> "" Then
   sqlStr = sqlStr & "where name like '%" & Trim(txtName.Text) & "%'"
  End If
  sqlDataAdapter.SelectCommand = New SqlCommand(sqlStr, sqlConnection)
  sqlConnection.Open()
  sqlDataAdapter.Fill(dataSet)
  sqlConnection.Close()

  DataGridView1.DataSource = dataSet.Tables(0)



 End Sub

 Private Sub FormSearchStudent_Load(sender As Object, e As EventArgs) Handles MyBase.Load

 End Sub
End Class