Florian wrote:
> Hi,
>
> I'm struggling a bit reading binary data from a database.
>
> Basically, I have a column in our table that has the binary type, and
> all I want to do is display that binary data in HEX. basically the
> table looks like this:
>
> binary_data binary(1024)
> binary_length int
>
> binary_length stores the number of bytes there are in the binary_data
> field.
> However it seems difficult to say the least to accomplish this with
> VBScript.
>
> First I tried to read the data by using the a for loop like:
>
> for a = 1 to binary_length
> response.write Hex(Asc(Mid(DBRS.Fields("binary_data").value, a, 1)))
> next
>
> but that gives me wrong results for some data, and it doesn't seem
> right to use the string function MID with binary data anyways.
>
> Then, I played around with the stream object. I had some success with
> that, but as it turns out I always had to save the stream to a file in
> order to "activate" it (I know this sounds odd).
>
> For example, I would successfully write the database field into the
> stream with
>
> stream.write DBRS.Fields("binary_data").value
>
> and then read the data into a variable like
>
> binaryData = stream.read

>
> This however would not work, unless I use the .SaveToFile option
> before the stream.read. I'm not sure why that is, but I can't always do
> that
> and it seems odd anyway. I wasn't even using the file, but for some
> reason I had to call that function.
>
> Can somebody give me a hint on how to do something as simple as
> getting binary data out of a table and display it?

Bob Barrows [MVP] wrote:
> Florian wrote:
>
>>Hi,
>>
>>I'm struggling a bit reading binary data from a database.
>>
>>Basically, I have a column in our table that has the binary type, and
>>all I want to do is display that binary data in HEX. basically the
>>table looks like this:
>>
>>binary_data binary(1024)
>>binary_length int
>>
>>binary_length stores the number of bytes there are in the binary_data
>>field.
>>However it seems difficult to say the least to accomplish this with
>>VBScript.
>>
>>First I tried to read the data by using the a for loop like:
>>
>>for a = 1 to binary_length
>>response.write Hex(Asc(Mid(DBRS.Fields("binary_data").value, a, 1)))
>>next
>>
>>but that gives me wrong results for some data, and it doesn't seem
>>right to use the string function MID with binary data anyways.
>>
>>Then, I played around with the stream object. I had some success with
>>that, but as it turns out I always had to save the stream to a file in
>>order to "activate" it (I know this sounds odd).
>>
>>For example, I would successfully write the database field into the
>>stream with
>>
>>stream.write DBRS.Fields("binary_data").value
>>
>>and then read the data into a variable like
>>
>>binaryData = stream.read
>
>
> The read method brings you to the end of the stream. You have to move back
> to the beginning in order to utilize the stream. Use the Position property
> to set the position to 0.
>
>
>>This however would not work, unless I use the .SaveToFile option
>>before the stream.read. I'm not sure why that is, but I can't always do
>>that
>>and it seems odd anyway. I wasn't even using the file, but for some
>>reason I had to call that function.
>>
>>Can somebody give me a hint on how to do something as simple as
>>getting binary data out of a table and display it?
>
>
> Not sure why you think this is simple ... :-)
>
>
> Check out the chunking methods in the ADO documentation at
> msdn.microsoft.com/library. GetChunk is one of them, and I think you may
> need to utilize it (I'm not sure 0 using the stream should work, but I've
> never done this)
>
> Bob Barrows