如何使用 VB.Net 从 SQL Server 2008 中检索 VARBINARY 值 [英] How to retrieve VARBINARY values from SQL Server 2008 using VB.Net

问题描述

我正在尝试使用 varBinary(max) 值填充列表视图.好吧，我实际上需要将每个 varBinary 写入一个 csv 文件，并且该表由 100 000 奇数行组成.

I'm trying to populate a listview with varBinary(max) values. Well, I actually need to write each varBinary into a csv file and the table consists of 100 000 odd rows.

我只是不知道如何检索数据类型！

I just don't know how to retrieve the datatype!

    Sub getInformation()
    Try
        If Not String.IsNullOrWhiteSpace(connString) Then
            Using cn As SqlConnection = New SqlConnection(connString)
                cn.Open()
                Using cmd As SqlCommand = New SqlCommand()
                    cmd.Connection = cn
                    Dim qry As String
                    qry = String.Format("SELECT [varBinaryField] FROM [dbX].[dbo].[tableX]")
                    cmd.CommandText = qry
                    cmd.CommandTimeout = 0

                    Using myReader As SqlDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
                        While (myReader.Read())
                            ListView1.Items.Add(myReader.get?WHAT?(0)) 'Help needed here.
                        End While
                    End Using
                End Using
            End Using
        End If
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

以下是 varBinary 代码之一的示例:

Heres an example of one of the varBinary codes :

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

推荐答案

    Using cn As SqlConnection = New SqlConnection("Server=.;Database=test;Trusted_Connection=True;")
        cn.Open()
        Using cmd As SqlCommand = New SqlCommand()
            cmd.Connection = cn
            Dim qry As String
            qry = String.Format("SELECT field FROM test.dbo.test")
            cmd.CommandText = qry
            cmd.CommandTimeout = 0
            Dim oFileStream As System.IO.FileStream
            oFileStream = New System.IO.FileStream("c:\bytes.txt", System.IO.FileMode.Append)
            Using myReader As SqlDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
                While (myReader.Read())
                    Dim data As Byte() = myReader(0)
                    oFileStream.Write(data, 0, data.Length)
                End While
                oFileStream.Close()
            End Using
        End Using
    End Using

更新:这里是:另一个关于 VB.NET 的例子

这篇关于如何使用 VB.Net 从 SQL Server 2008 中检索 VARBINARY 值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！