如何将MS Access中特定列数据逐月相加并在vb.net中转到textbox

SELECT Format([日期字段], 'yyyy-mm') AS 月份, SUM([特定列名]) AS 总和
FROM 表名
GROUP BY Format([日期字段], 'yyyy-mm')

Imports System.Data.OleDb

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\路径\数据库文件.accdb"
        Dim query As String = "SELECT Format([日期字段], 'yyyy-mm') AS 月份, SUM([特定列名]) AS 总和 FROM 表名 GROUP BY Format([日期字段], 'yyyy-mm')"

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

            Using command As New OleDbCommand(query, connection)
                Dim reader As OleDbDataReader = command.ExecuteReader()

                While reader.Read()
                    Dim month As String = reader("月份").ToString()
                    Dim sum As Integer = Convert.ToInt32(reader("总和"))

                    TextBox1.Text += month & ": " & sum & Environment.NewLine
                End While

                reader.Close()
            End Using

            connection.Close()
        End Using
    End Sub
End Class