Hi. There's nothing wrong with your code, but JDBC-ODBC bridges suck.
I have never yet heard of a commercial-quality high-performance one.
Sun's is old, buggy, not threadsafe, and unsupported. If you have to use
it (and also to test any other candidate driver), you could try:

Statement s = m_dbAccess.getConnection().createStatement();

StringBuffer myHomeGrownBatch = new StringBuffer();
"INSERT INTO
 tb_Clients_History VALUES(?,?...)");

 while(...)
 {
     myHomeGrownBatch.append(
            "INSERT INTO tb_Clients_History VALUES("
            + "'" + "data0" + "'"
            + ", "
     .....
            + "'" + "data40" + "'"
            + ")\n"
     );
 }
 s.execute(myHomeGrownBatch.toString());
 s.close();
 m_dbAccess.getConnection().commit();

Note the newline after each line in the batch. If the DBMS
accepts multiple lines like that (like MS SQLServer, Sybase
etc) fine. Some DBMSes like Oracle would need a string like:

"BEGIN
insert into ....;
insert into ....;
END;"

Just make one big string and send it to the DBMS in one call.
A driver has to be very good to beat this technique for a
single client. (This may not be optimal for many clients
repeating it, and a good dirver may be a bit slower with
a proper prepared statement, but allowing much more concurrency.

HTH,
Joe Weinstein at BEA Systems

Joe Weinstein at BEA Systems.

2 things here:

1)  The Sun jdbc-odbc bridge is not ready for production.  If you look
at the docs,  it says basically that you are on your own,  and it was
made just to give something to test against.  Bridges can work
satisfactorily,  but the Sun one is rather lowest common denominator.

2)  I'm not sure you are using a prepared statement to it's best
advantage.  I'd need to see a little more of the code.  You need to use
the same statement in a loop,  changing only the
"prepUpdate.setString(1,"data0");" values.

Example code from
http://java.sun.com/docs/books/tutorial/jdbc/basics/prepared.html

PreparedStatement updateSales;
String updateString = "update COFFEES " +
             "set SALES = ? where COF_NAME like ?";
updateSales = con.prepareStatement(updateString);
int [] salesForWeek = {175, 150, 60, 155, 90};
String [] coffees = {"Colombian", "French_Roast", "Espresso",
            "Colombian_Decaf", "French_Roast_Decaf"};
int len = coffees.length;
for(int i = 0; i < len; i++) {
        updateSales.setInt(1, salesForWeek[i]);
        updateSales.setString(2, coffees[i]);
        updateSales.executeUpdate();
    }

If you interested,  you get a demo jdbc-odbc bridge (Type 1),  or a
Type 3 jdbc driver for oracle here:

http://www.openlinksw.com

If you run into issues,  open a support cand ask for me.

Jay Grubb
Technical Consultant
OpenLink Software
Web: http://www.openlinksw.com:
Product Weblogs:
Virtuoso: http://www.openlinksw.com/weblogs/virtuoso
UDA: http://www.openlinksw.com/weblogs/uda
Universal Data Access & Virtual Database Technology Providers

Hi!

To Joe Weinstein:
Thank you for your propose, I will try the StringBuffer.

To Jay Grubb:
In my program I use the PreparedStatement with different values in the
loop. Here I had should write

prepUpdate.setString(1,data0[i]);
   .....
prepUpdate.setString(40,data40[i]);

I know that the Sun Bridge is not ready for production (I already read
the docs) but I don't want to buy a commercial driver.
Do you know a free one for MS Access?
And if I have to deal with a Oracle db I will try your driver.

Thanks to all!

Regards,

Martin Oberhammer