Getting zero terminated string through (both jTDS & MS) jd..

Hi,

I am having a curious problem that I verified now with both the
MS JDBC Driver 1.2 and jTDS (both show same strange behaviour).
The Strangeness is that it looks like I am receiving 0 terminated
strings through the jTDS/MS JDBC driver, except the driver
does not realize this. This means, a variable length column, eg.:
varchar(15) is always 15 characters in length and the correct length
is zero terminated.

I am working with a varchar column and when I use the getString()
Method of the ResultSet Object I receive Strings with binary zeros.
I also verified this behaviour with getCharacterStream() function.

The problem shows as follows:

String in Table Received String (In Order of Query)
---------------------------------------------------------
dirk dirk^^^^^^^^^^^
db db^k^^^^^^^^^^^
hello hello^^^^^^^^^^
x x^llo^^^^^^^^^^
---------------------------------------------------------

'^' => I use this character to escape binary zero

To me this looks like a fixed length buffer is used and
the getString() method always returns the full size, even
though the datatype is varchar(15). I can verify this problem
only in connection with Microsoft SQL Server 2000. I have
tested with other Microsoft/Sybase Servers and can not
re-create this behaviour(?).

Does any one know any setting or config I could try?
Is this a known bug or is there a workaround? Please
tell me if you need config infos I'll see if I can get it for
posting here...

Thanks a lot for any helpful hints,
Cheers Dirk

Hi. Please write a tiny standalone program that demonstrates the problem, eg:

import java.sql.*;
import java.util.*;

public class foo
{
public static void main(String argv[])
throws Exception
{
Connection c = null;
try
{
Properties props = new Properties();
Driver d = new com.microsoft.sqlserver.jdbc.SQLServerDriver();

props.put("user", "sa");
props.put("password", "secret");

c = d.connect("jdbc:sqlserver://localhost:1433", props );

System.out.println("Driver version is " + c.getMetaData().getDriverVersion() );
System.out.println("DBMS version is " + c.getMetaData().getDatabaseProductVersion() )
;
Statement s = c.createStatement();
s.executeUpdate("CREATE TABLE #foo(bar varchar(25))");
s.executeUpdate("insert #foo values('a')");
s.executeUpdate("insert #foo values('bbbbbbbb')");
s.executeUpdate("insert #foo values('ccccccccccccccccc')");
s.executeUpdate("insert #foo values('dddddddddddddddddddd')");

ResultSet rs = s.executeQuery("select * from #foo");
while (rs.next()) System.out.println( ... whatever you find odd... );
}
catch(Exception exception1)
{
exception1.printStackTrace();
}
finally
{
if (c != null) try {c.close();} catch (Exception ignore){}
}
}
}


dirk_bahle DeleteThis @gmx.de wrote:

> Hi,
>
> I am having a curious problem that I verified now with both the
> MS JDBC Driver 1.2 and jTDS (both show same strange behaviour).
> The Strangeness is that it looks like I am receiving 0 terminated
> strings through the jTDS/MS JDBC driver, except the driver
> does not realize this. This means, a variable length column, eg.:
> varchar(15) is always 15 characters in length and the correct length
> is zero terminated.
>
> I am working with a varchar column and when I use the getString()
> Method of the ResultSet Object I receive Strings with binary zeros.
> I also verified this behaviour with getCharacterStream() function.
>
> The problem shows as follows:
>
> String in Table Received String (In Order of Query)
> ---------------------------------------------------------
> dirk dirk^^^^^^^^^^^
> db db^k^^^^^^^^^^^
> hello hello^^^^^^^^^^
> x x^llo^^^^^^^^^^
> ---------------------------------------------------------
>
> '^' => I use this character to escape binary zero
>
> To me this looks like a fixed length buffer is used and
> the getString() method always returns the full size, even
> though the datatype is varchar(15). I can verify this problem
> only in connection with Microsoft SQL Server 2000. I have
> tested with other Microsoft/Sybase Servers and can not
> re-create this behaviour(?).
>
> Does any one know any setting or config I could try?
> Is this a known bug or is there a workaround? Please
> tell me if you need config infos I'll see if I can get it for
> posting here...
>
> Thanks a lot for any helpful hints,
> Cheers Dirk