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blob (word or pdf?)

  • July 7, 2004 at 3:17 am

    #84963

    I have a table in SQL Server that has an Image (also called BLOB) type field.

    I would like to know what kind of data is stored in the blob fields. I know that there are MS Word blobs, pdf blobs, and gif blobs but I dont know which are which.

    Is there any way to determine what kind of info is stored in these blob fields.

    i do have an in-elegant way (with asp:

    response.binarywrite  rsBlob.Fields("binary_doc").GetChunk(1000)

    which yields some gobbledygook:

     - ÿÿÿÿDocumentWord.Document.8Word.Document.8|ÐÏࡱá>þÿ

    but with a visual examintaion it is possible to spot if its Word or not

     

    Is there a more ELEGANT way??????

    Thanks

  • July 8, 2004 at 5:28 pm

    #513934

    In Image(Blob) Data Type you can put any data, pdf, word, gif, your own class object into the database table field.

    Using ADODB stream to load the object into field:

      Set mstream = New ADODB.Stream

            mstream.Type = adTypeBinary

            mstream.Open

            mstream.LoadFromFile (App.Path & "\" & "acrobat.pdf")

            rsDocument.AddNew

            rsDocument.Fields("Data").Value = mstream.Read

            rsDocument.Update

    You can still use the GetChunk methods and do the same thing, in some cases give you control over the data.

    Putting files into database is not an ideal for large number of files.  You will get performance problems.  The best is to keep it off site on disk and reference to the file. 

    Hope this helps.

     

     

     

  • July 12, 2004 at 10:39 pm

    #514325

    mstream is an ado stream,

    rsdocument is ??

    how declared ??

    how linked to a table, coumn ??

    next,

    how to read an image data type (blob):

    1. Into a file

    2. Into memory

    EM

  • July 20, 2004 at 10:01 pm

    #515396

    Assumeded that you have a table called ImageData with ImageNo varchar(50),  Data(Image) Fields

      Dim mstream As ADODB.Stream

      Dim rsDocumentAs ADODB.Recordset

       Set mstream = New ADODB.Stream

       mstream.Type = adTypeBinary

       rsDocument.Open "Select top 1 * from ImageData",  strActiveConnectionString, adOpenKeyset, adLockOptimistic)

        mstream.LoadFromFile (App.Path & "\" & "acrobat.pdf")

       rsDocument.AddNew

       rsDocument.Fields("Data").Value = mstream.Read

       rsDocument.Fields("ImageNo").Value = "acrobat"

       rsDocument.Update

    'To Retrieve it from the server

      Dim rsImage As ADODB.Recordset

       Dim mstream As ADODB.Stream

       

        Set rsImage = New ADODB.Recordset

        rsImage.Open "select * from ImageData where ImageNo = '" & strImageFile & "'", strActiveConnectionString, adOpenStatic

       

        If rsImage.RecordCount <> 0 Then

          Set mstream = New ADODB.Stream

          mstream.Type = 1

          mstream.Open

         

          mstream.Write rsImage.Fields("Data").Value

          mstream.SaveToFile strFileName, adSaveCreateOverWrite

          mstream.Close   

        Else

          msgbox "Record not found with given image name file"

        End If

        rsImage.Close

    Hope this helps a bit more...

    Please look up on the Microsoft MSDN for future help.

     

  • July 21, 2004 at 2:15 am

    #515432

    thanks yan_aung

    that helps

  • February 16, 2010 at 4:51 am

    #1119167

    it does n't work for me.I can save the Pdf file and i can not open it.

    it is saying that "Adobe reader could not open pdf.because it is either not a supported file type or because the file has been damaged".

    Can any one give me the solution?

    thanks

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