Tornado API Library - V12.30.08

z.dbBLOB Property

Display BLOB fields in an inline or HREF linked manner.

[Visual Basic]
Public Property dbBLOB As String
public string dbBLOB {set;}

Property Value

Obj.dbBLOB = "Field| Context| Label | Offset"

FieldFieldNameOrNumber is the Database field that is of BLOB type (128, 204, 205).
Context The HTML context type (image/jpg, image/bmp, image/gif, application/msexcel etc.) These can be found in your browser’s “Helper Apps”).

2005 new implementation - Auto (Autodetect BLOB Type - gif, jpg, png, bmp and pdf only). Default = "text/html" which covers Ascii mode also. You can mix the type of Blobs stored in the field and display in the inline mode. Inline does not need any context. This implementation is truely amazing.

LabelThis text will be displayed when Linked images are used instead of in-line images.
Offset Every database implements BLOBs differently. When binary objects are stored in the data field with an attached header, you must determine how many bytes (if any) are delivered in front of the actual binary data. Some examples are:

* ACCESS OLE-OBJ field containing BMP images – Offset = 78 (NWIND Employee Table example)

* Borland Paradox’s BLOB field storing images (Biolife example) – Offset = 8

Set Offset to –1 if hyperlinking is not desired. In this case, the image will be displayed “in-line”.

QuickProp Keyword Abbreviation



Different DB has their BLOB fields defined differently. The fields are sometimes stored with a header. Use must know the format of these BLOBs in order to have them displayed properly.

For inline display, dbBookMark must be specified. Only the table name of the BookMark is used upon re-entrance image display.


  .dbBlob = "field=Pic|context=auto|label=Hyperlink to Blob|offset=0"
  .dbBlob = "field=logo|context=image/gif|label=browser|offset=0"
<script language="vb" runat="server">
Sub Page_Load(Source as Object, E as EventArgs)
Dim BGif As New Tornado.Z()
  With BGif
    .dbQP = "U=92|S=14|dt=SQL|th=ti=Blob Demo"
    .dbSQL="SELECT pub_id, logo From pub_info"
    .dbBookMark = "pub_info;0"      
    .dbBlob = "field=logo|context=image/gif|label=browser|offset=0"
  End With
End Sub

See Also

z Class | Tornado Namespace