FreeTDS Development Group

[Craig Spannring <cts AT internetcds.com>]

Brian Bruns writes:
 > I don't know if this will help or not, but return results usually have a
 > size for variable data or the data alone for fixed length data, thus 0
 > could indicate a length of 0 or null.

I think I've got the stored procedure calls figured out (for TDS 4.2).
If anyone out there knows for sure if this is right or wrong please
let me know.

The packet type in the 8 byte header is 0x03.  The data in the packet
is-


     1 byte      variable     4 bytes   variable   1byte 1byte    variable   
1byte 1byte          variable
   
+---------------------------------------------+------+-------+----------+------+-------+
     +--------+
   | procname |  procname  | unknown1 | param1   | 0x00 | 0x00  | param2   | 
0x00 | 0x00  | ... | paramN |
   | length   |            |          |          |      |       |          |  
    |       |     |        |
   
+---------------------------------------------+------+-------+----------+------+-------+
     +--------+

The 4 unknown bytes seem to always be 0x00.  

The two 0x00 bytes that separate each parameter are somewhat confusing.
They seem to be a complete waste of data.  Perhaps I'm missing
something here.

The parameters seem to be of the form

     1 byte      1 byte     1 byte   variable
   +----------+-----------+--------+---------+
   | variable |  maximum  | actual |  data   |
   | length   |  possible | length |         |
   | datatype |  length   |        |         |
   +----------+-----------+--------+---------+

or
      1 byte     
   +----------+--------+
   | fixed    |  data  |
   | length   |        |
   | datatype |        |
   +----------+--------+

The datatype byte comes from the SYB* definitions in tds.h



--
=======================================================================
 Life is short.                  | Craig Spannring
      Ski hard, Bike fast.       | cts AT internetcds.com
 --------------------------------+------------------------------------
 Any sufficiently perverted technology is indistinguishable from Perl.
=======================================================================