同济大学SQL数据库实验10
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Imports System.Data.SqlClient
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim mysql As String = "insert into sc values('" & Me.TextBox1.Text & "','" &
Me.TextBox2.Text & "'," & Val(Me.TextBox3.Text) & ")"
Dim myconn As New SqlConnection("database=university;data source=(local);integrated security=true;")
Dim mycmd As New SqlCommand(mysql, myconn)
myconn.Open()
Try
mycmd.ExecuteNonQuery()
Catch ex As Exception
MsgBox(ex.Message)
End Try
myconn.Close()
End Sub
End Class
2、Imports System.Data.SqlClient
Public Class Form1
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
Dim mysql As String= "select * from sc where snum='"& ComboBox1.SelectedItem.ToString() & "'"
Dim mysql2 As String = " select sname from student where snum='" +
ComboBox1.SelectedItem.ToString() + "'"
Dim myconn As New SqlConnection("database=university;data source=(local);integrated
security=true;")
Dim mycmd As New SqlCommand(mysql, myconn)
Dim mycmd2 As New SqlCommand(mysql2, myconn)
Dim sum As Integer = 0
Dim count As Integer = 0
Dim stname As String
myconn.Open()
stname = mycmd2.ExecuteScalar()
Dim mydatareader As SqlDataReader
mydatareader = mycmd.ExecuteReader()
Do While mydatareader.Read()
sum = sum + mydatareader.Item(2)
count = count + 1
Loop
mydatareader.Close()
myconn.Close()
sum = sum / count
TextBox2.Text = stname
TextBox3.Text = count
TextBox4.Text = sum
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load ComboBox1.Focus()
Dim mysql As String = "select * from student"
Dim myconn As New SqlConnection("database=university;data source=(local);integrated security=true;")
Dim mycmd As New SqlCommand(mysql, myconn)
myconn.Open()
Dim mydatareader As SqlDataReader
mydatareader = mycmd.ExecuteReader()
Do While mydatareader.Read()
ComboBox1.Items.Add(mydatareader.Item(0))
Loop
End Sub
End Class