浅谈如何使用vb.net从数据库中提取数据
1.设置从Model中的Sub Main 启动
2.程序结构
3.Model1
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
4.FormStudentSysMain.vb
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
5.FormSearchStudent.vb
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
6.运行结果