form7.vb

来自「学生成绩管理系统」· VB 代码 · 共 35 行

Public Class Form7

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Module1.db()
        conn.Open()
        Dim tab71 As New DataTable

        cmd.CommandText = "select cno from course"
        da.SelectCommand = cmd

        da.Fill(ds, "tab71")
        Dim i As Integer
        For i = 0 To ds.Tables("tab71").Rows.Count - 1
            If TextBox1.Text = ds.Tables("tab71").Rows(i).Item(0) Then
                MsgBox("此课程已存在,请重新输入!")
                conn.Close()

                Exit Sub

            End If
        Next
        cmd.CommandText = "insert into course(cno,cname,ccredit) values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "'  )"


        cmd.ExecuteNonQuery()
        MsgBox("成功")
        conn.Close()

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.Close()

    End Sub
End Class