Handling Special Characters in Oracle JDBC et al

Question

Hi all
I am writting a programme to do the following ..
a)Download xml data from the internet... by means of URL openConnection etc.
b) Insert parts of the xml data into a oracle database ...
Quite simple .. but ;)
How ever there is a integerity constrain of NOT NULL and UNIQUE on one of the columns on the database ...
if the word Galen exists and the code tries to insert G�len ( note � is a character on its own NOT a with ' )
its gives a Integrity violation.
I tried the following
String name = "G�len";/// comming from xml after parsing etc ...
Statement stmt = conn.createStatement();
stmt.executeUpdate("INSERT INTO ABC VALUES("+name+")" and also tried
String name = "G�len";/// comming from xml after parsing etc ...
PreparedStatement ps = conn.prepareStatement();
ps.setString(1,name);
ps.executeUpdate("INSERT INTO ABC VALUES( ? )"); and few other variations to the above procedure ....
Can any one tell me what could be the reason one possible cause could that Oracle does a transparent character set conversion on all data that it is about to update / insert ... If so what is the work around cause "Galen" and "G�len" are definatly two different names..
Also interestingly I tries to execute the following query
SELECT name FROM ABC WHERE name = 'G�len' vie jdbc using the above methods and it returns a emty result set.
So while doing a query oracle refuses to accept G�len as a existing word where as when the time comes to insert G�len it issues a integrity constraint violation :(
O/S for client code and Oracle server : Compaq Tru64 UNIX
Characters set for Compaq Tru64 UNIX V5.0A : ISO8859_1
Character set for Oracle is US7ASCII

Answer 1

You should use Prepared statements, it's easier and faster.
In your code you have mixed it up a bit. You wrote:
String name = "G�len";/// comming from xml after parsing etc ...
PreparedStatement ps = conn.prepareStatement();
ps.setString(1,name);
ps.executeUpdate("INSERT INTO ABC VALUES( ? )");
It should be
String name = "G�len";/// comming from xml after parsing etc ...
PreparedStatement ps = conn.prepareStatement("INSERT INTO ABC VALUES( ?)");
ps.setString(1,name);
ps.executeUpdate();
In other words, you prepare your statements and then you just use the set methods and execute. If you're looping over the XML-file you should just prepare the staments onece and then use it over and over again. This is one of the strengths with PreparedStatements.
Let's assume you have all your names in an array called name, use the following code instead:
PreparedStatement ps = conn.prepareStatement("INSERT INTO ABC VALUES( ?)");
for(int i=0; i < names.length();i++){
ps.setString(1, names);
ps.executeUpdate();
Of course, you might use ArrayList or some other Collection instead, this is just to show how to reuse PreparedStatements.
/Fredrik