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Reading Binary Data from SQL Request

  • To: mathgroup at smc.vnet.net
  • Subject: [mg110353] Reading Binary Data from SQL Request
  • From: Stephan Schiffels <stephan80 at mac.com>
  • Date: Tue, 15 Jun 2010 02:28:12 -0400 (EDT)

Dear group,

I use DatabaseLink to retrieve binary data from a database.
So lets say, I retrieve the data as:

Needs["DatabaseLink`"];
conn = OpenSQLConnection["myDB"];
data = SQLSelect[conn, "myTable", "myBinaryField"];

Then the type of data[[1,1]] is an SQLBinary-Object, containing a list of bytes, accessible as the first item of the SQLBinary-Wrapper: data[[1,1.1]]

I need to read this binary data as a sequence of double precision floating point numbers, similar to the following command:

BinaryRead[stream, "Real64"], where "stream" is a file on the harddisk.

I have not figured out how to do this with binary data that is already in memory, rather then in a file. All I can find in the documentation is concerned with File I/O.

What I can do is to use a temporary file:

BinaryWrite["tmp", data[[1,1,1]]];
Close["tmp"];
num = BinaryRead["tmp", "Real64"];

But there clearly should be a way to avoid the creation of binary files here...

I appreciate any help.

Thanks,

Stephan



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