visual basic查找数据库合计

Imports System.Data.SqlClient

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim connectionString As String = "Data Source=数据库服务器地址;Initial Catalog=数据库名称;User ID=用户名;Password=密码"
        Dim sql As String = "SELECT SUM(字段名) FROM 表名"

        Using connection As New SqlConnection(connectionString)
            connection.Open()

            Using command As New SqlCommand(sql, connection)
                Dim result As Object = command.ExecuteScalar()

                If result IsNot DBNull.Value Then
                    Dim total As Integer = Convert.ToInt32(result)
                    MessageBox.Show("合计值为: " & total.ToString())
                Else
                    MessageBox.Show("没有数据可供合计")
                End If
            End Using
        End Using
    End Sub
End Class