ACCESS数据库升级到SQL数据库(二) 图片的存储

 

1、使用ODBCADAPTER进行更新，需要加入Dim db As New Odbc.OdbcCommandBuilder(ada)

        dim myfilestream As New System.IO.FileStream(filename, IO.FileMode.Open)
        Dim data(myfilestream.Length) As Byte
        
        myfilestream.Read(data, 0, myfilestream.Length)
        myfilestream.Close()

        Dim ada As Odbc.OdbcDataAdapter
        Dim rs As New DataTable
        Dim c_str As String
        c_str = "select * from *"
        If connect.State <> ConnectionState.Open Then
            connect.Open()
        End If
        ada = New Odbc.OdbcDataAdapter(c_str, connect)
        ada.Fill(rs)
        rs.Rows(0)("图片") = data
        '必须加入下一行进行更新
        Dim db As New Odbc.OdbcCommandBuilder(ada)
        ada.Update(rs)
        ada.Dispose()

2、使用SQL语句储存       

        Dim c_str As String
        c_str = "update 制件信息 set 图片=@data  where *"
        Dim mycommand As New Odbc.OdbcCommand(c_str)
        mycommand.CommandType = CommandType.StoredProcedure
        mycommand.Connection = connect
        Dim p As New Odbc.OdbcParameter("@data", Odbc.OdbcType.Image)
        p.Value = data
        mycommand.Parameters.Add(p)
        If connect.State <> ConnectionState.Open Then
            connect.Open()
        End If
        Try
            mycommand.ExecuteNonQuery()
        Catch ex As Exception
            MsgBox("图片写人失败" & vbNewLine & ex.Message)
        End Try

调试过程中总出现无效的精度值错误，将代码改为

        Dim c_str As String
        c_str = "update 制件信息 set 图片=?  where *"
        Dim mycommand As New Odbc.OdbcCommand(c_str)
        mycommand.CommandType = CommandType.StoredProcedure
        mycommand.Connection = connect
        Dim p As New Odbc.OdbcParameter("@P1", Odbc.OdbcType.Image)
        p.Value = data
        mycommand.Parameters.Add(p)
        If connect.State <> ConnectionState.Open Then
            connect.Open()
        End If
        Try
            mycommand.ExecuteNonQuery()
        Catch ex As Exception
            MsgBox("图片写人失败" & vbNewLine & ex.Message)
        End Try

顺利通过调试。。。。。。。。。。。居然要采用？这种古老的变量申明方式，彻底无语