FreeTDS Development Group

[Nathaniel Talbott <nathaniel AT talbott.ws>]

I'm using Ruby/ODBC with FreeTDS (connecting to a MSSQL server), and 
I've discovered a bug. The only problem is, I'm having difficulty 
determining whose bug it is...

Here's some code:

  require 'odbc'

  db = ODBC::connect("sedev", "", "")
  db.do("DROP TABLE test") rescue nil
  db.do("CREATE TABLE test (tid INTEGER IDENTITY, thing INTEGER)")
  db.do("INSERT INTO test (thing) VALUES (1234)")
  db.do("INSERT INTO test (thing) VALUES (?)", 1234)
  s = db.run("SELECT * FROM test")
  while(row = s.fetch)
    p row
  end
  s.drop

Output:

  ntalbott@proxytest:~/cvs/se-2/se/src$ ruby t2.rb
  ["1", 1234]
  ["2", 1]

(If you want to get your hands on Ruby/ODBC, check out 
http://www.ch-werner.de/rubyodbc/. I'm actually using a newer, 
pre-release version, but I don't think anythings changed that affects 
this problem.)

The issue centers around FreeTDS not supporting SQLDescribeParam. This 
is valid, and Ruby/ODBC simply marks the parameter as SQL_VARCHAR. So 
far so good. Next Ruby/ODBC sees that the type being bound to the 
column is a (Ruby) integer, and so it marks the C type of the parameter 
as SQL_C_LONG. That should be right, too. Then Ruby/ODBC sets to 1 the 
StrLen_or_IndPtr argument (FreeTDS names the argument pcbValue) of 
_SQLBindParameter. The issue seems to be that FreeTDS (or MSSQL?) 
truncates the value based on this last argument after casting from a 
SQL_C_LONG to a SQL_VARCHAR. Meaning I end up with 1 instead of 1234.

The question is, is Ruby/ODBC wrong to set the length to 1? Or is 
FreeTDS wrong to use that value and truncate the value. I'm leaning 
towards the latter, but I'm having difficulty figuring out where to fix 
FreeTDS.

Any ideas? I can give you a TDSDUMP if that would help.

Thanks,


Nathaniel

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