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发信人: Jobs (温少), 信区: Visual
标 题: VB如何编程实现将一幅图像存入sql65的image?
发信站: BBS 荔园晨风站 (Fri Dec 10 16:42:32 1999), 站内信件
发信人: LaoWei (独孤一剑), 信区: VisualBasic
标 题: Re: VB如何编程实现将一幅图像存入sql65的image字段呀
发信站: BBS 水木清华站 (Sat Nov 7 09:17:05 1998)
【 在 soilder (sun) 的大作中提到: 】
: 那位大虾给讲讲,感激不尽
使用 AppendChunk 和 GetChunk 方法
下面示例说明使用 AppendChunk 和 GetChunk 方法将基于数据页
的、大的二进制对象 (BLOB) 数据写入远程数据源。这段代码需要
一个名为 Chunks 的表,表中带有字符、文本、以及图象域。为了
建立该表,提出如下代码作为对测试数据库的查询操作:
CREATE TABLE Chunks (ID integer identity NOT NULL, PName
char(10) NULL, Description TEXT NULL, Photo IMAGE NULL)
CREATE UNIQUE INDEX ChunkIDIndex on Chunks(ID)
一旦建立了该表,就需要一个或多个 .BMP 或其它合适的、可由
PictureBox 控件定位装入的图形图象。
Option Explicit
Dim en As rdoEnvironment
Dim Qd As rdoQuery
Dim Cn As rdoConnection
Dim Rs As rdoResultset
Dim SQL As String
Dim DataFile As Integer, Fl As Long, Chunks As Integer
Dim Fragment As Integer, Chunk() As Byte, I As Integer
Const ChunkSize As Integer = 16384
Private Sub Form_Load()
Set en = rdoEnvironments(0)
Set Cn = en.OpenConnection(dsname:="", _
Connect:="UID=;PWD=;DATABASE=WorkDB;" _
& ""Driver={SQL Server};SERVER=Betav486", _
prompt:=rdDriverNoPrompt)
Set Qd = Cn.CreateQuery("TestChunk", "Select * from Chunks Where PName = ?")
End Sub
Private Sub LoadFromFile_Click()
'
' 将文件定位并为该文件设置文件名。
'
With CommonDialog1
.Filter = "Pictures(*.bmp;*.ico)|*.bmp;*.ico"
.ShowOpen
FileName = .FileName
End With
End Sub
Private Sub ReadFromDB_Click()
If Len(NameWanted) = 0 Then _
NameWanted = InputBox("Enter name wanted", "Animal")
Qd(0) = NameWanted
Set Rs = Qd.OpenResultset(rdOpenKeyset, rdConcurRowver)
If Rs Is Nothing Or Rs.Updatable = False Then
MsgBox "Can't open or write to result set"
Exit Sub
End If
If Rs.EOF Then
MsgBox "Can't find picture by that name"
Exit Sub
End If
Description = Rs!Description
DataFile = 1
Open "pictemp" For Binary Access Write As DataFile
Fl = Rs!Photo.ColumnSize
Chunks = Fl \ ChunkSize
Fragment = Fl Mod ChunkSize
ReDim Chunk(Fragment)
Chunk() = Rs!Photo.GetChunk(Fragment)
Put DataFile, , Chunk()
For I = 1 To Chunks
ReDim Buffer(ChunkSize)
Chunk() = Rs!Photo.GetChunk(ChunkSize)
Put DataFile, , Chunk()
Next I
Close DataFile
FileName = "pictemp"
End Sub
Private Sub SaveToDB_Click()
If Len(NameWanted) = 0 Then _
NameWanted = InputBox("Enter name for this" _
& " picture", "Animal")
Qd(0) = NameWanted
Set Rs = Qd.OpenResultset(rdOpenKeyset, _
rdConcurRowver)
If Rs Is Nothing Or Rs.Updatable = False Then
MsgBox "Can't open or write to result set"
Exit Sub
End If
If Rs.EOF Then
Rs.AddNew
Rs!PName = NameWanted
If Description = "" Then _
Description = InputBox("Describe the picture", _
"Don't care")
'Rs!Description = Description
Else
Rs.Edit
End If
DataFile = 1
Open FileName For Binary Access Read As DataFile
Fl = LOF(DataFile) ' 文件中数据的长度
If Fl = 0 Then Close DataFile: Exit Sub
Chunks = Fl \ ChunkSize
Fragment = Fl Mod ChunkSize
Rs!Photo.AppendChunk Null
ReDim Chunk(Fragment)
Get DataFile, , Chunk()
Rs!Photo.AppendChunk Chunk()
ReDim Chunk(ChunkSize)
For I = 1 To Chunks
Get DataFile, , Chunk()
Rs!Photo.AppendChunk Chunk()
Next I
Close DataFile
Rs.Update
End Sub
Private Sub FileName_Change()
Picture1.Picture = LoadPicture(FileName)
End Sub
--
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