演示环境:
数据库机器名 :s_test
登陆名 :sa
密码 :7890
数据库名 db_test
下面建立一个表:
create table tb_test(id int identity(1,1),photo image,constraint pk_tb_test primary key(id))
一、将硬盘上的文件保存至数据库(VB.NET)
'----------------------------------------------------------
'----------------------------------------------------------
'下面的示例将c:\1.jpg文件保存至数据库的tb_test表中
'----------------------------------------------------------
'----------------------------------------------------------
Imports System.IO
Imports System.Data.sqlClient
Public Class image
Shared Sub Main()
'读入文件数据
Dim fs = New FileStream("c:\1.jpg",IO.FileMode.Open,IO.FileAccess.Read)
Dim imgData(fs.Length - 1) As Byte
fs.Read(imgData,fs.Length - 1)
fs.close()
Dim tempConnection As New sqlConnection
Dim tempAdapter As sqlDataAdapter
Dim tempDataSet As New DataSet
'打开数据库连接
tempConnection.ConnectionString = "server=s_Test;uid=sa;pwd=7890;database=db_test"
tempConnection.open()
tempAdapter = New sqlDataAdapter("SELECT * FROM tb_test WHERE 1=0",tempConnection)
Dim cb As New sqlCommandBuilder(tempAdapter)
tempAdapter.Fill(tempDataSet)
'插入一条记录
Dim tempDaTarow As DaTarow
tempDaTarow = tempDataSet.Tables(0).NewRow()
tempDaTarow("photo") = imgData
tempDataSet.Tables(0).Rows.Add(tempDaTarow)
tempAdapter.Update(tempDataSet)
tempConnection.Close()
End Sub
End Class
二、将数据库中的文件保存至硬盘(VB.NET)
'----------------------------------------------------------
'----------------------------------------------------------
'下面的示例将数据库的tb_test表中第一条记录的photo保存至c:\2.jpg
'----------------------------------------------------------
'----------------------------------------------------------
Imports System.IO
Imports System.Data.sqlClient
Public Class image
Shared Sub Main()
Dim tempConnection As New sqlConnection
Dim tempAdapter As sqlDataAdapter
Dim tempDataSet As New DataSet
'打开数据库连接,取出数据
tempConnection.ConnectionString = "server=s_test;uid=sa;pwd=7890;database=db_test"
tempConnection.open()
tempAdapter = New sqlDataAdapter("SELECT TOP 1 * FROM tb_test",tempConnection)
tempAdapter.Fill(tempDataSet)
tempConnection.Close()
If tempDataSet.Tables(0).Rows.Count > 0 Then
'将文件保存到硬盘文件c:\2.jpg
Dim imgData() As Byte
imgData = tempDataSet.Tables(0).Rows(0).Item("photo")
Dim fs As FileStream
fs = File.Create("c:\2.jpg",imgData.Length - 1)
fs.Write(imgData,imgData.Length - 1)
fs.Close()
End If
End Sub
End Class
三、更新数据库中保存的文件 '---------------------------------------------------------- '---------------------------------------------------------- '下面的示例用将数据库的tb_test表中第一条记录的photo更新为c:\2.jpg '---------------------------------------------------------- '---------------------------------------------------------- Imports System.IO Imports System.Data.sqlClient Public Class image Shared Sub Main() '读取文件 Dim fs = New System.IO.FileStream("c:\2.jpg",IO.FileAccess.Read) Dim imgData(fs.Length - 1) As Byte fs.Read(imgData,fs.Length - 1) fs.close() Dim tempConnection As New sqlConnection Dim tempAdapter As sqlDataAdapter Dim tempDataSet As New DataSet '打开数据库连接,取出数据 tempConnection.ConnectionString = "server=s_test;uid=sa;pwd=7890;database=db_test" tempConnection.open() tempAdapter = New sqlDataAdapter("SELECT TOP 1 * FROM tb_test",tempConnection) tempAdapter.Fill(tempDataSet) '更新数据 Dim cb As New sqlCommandBuilder(tempAdapter) tempDataSet = New DataSet tempAdapter.Fill(tempDataSet) tempDataSet.Tables(0).Rows(0).Item("photo") = imgData tempAdapter.Update(tempDataSet) tempConnection.Close() End Sub End Class