Reading and writing to a MySQL database with Java

Anyone knows what's the best way to read and write from a MySQL database?

> Anyone knows what's the best way to read and write
from a MySQL database?
Yep!
The Java� Tutorial - Trail: JDBC� Database Access
MySQL Reference Manual
MySQL Connector/J Documentation
Driver/Datasource Class Names, URL Syntax and Configuration Properties for Connector/J
Best of luck!
~

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Is it possible to insert data into a MySQL database with Java?

Hello everyone!
I would like to know, if it's possible to insert data into a MySQL database, with a JFrame inside a servlet?
When the JFrame is first created it calls this method:
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            });And this is my "execute()" method:
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     * - And executes the SQL queries.
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            String fullName = firstName + " " + lastName;
            printer.write("Employee " + fullName + " added.</br>");
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This is what I use to insert into mysql. It works on windows.
try {
            Class.forName("com.mysql.jdbc.Driver");
            String connectionUrl = "jdbc:mysql://" + loadip + "/custsig?" +
                    "user=root&password=";
            Connection con = DriverManager.getConnection(connectionUrl);
            newproc = jTextField1.getText();
            newsoft = jTextField2.getText();
            newdeb = jTextField3.getText();
            newcust = jTextField4.getText();
            if (newcust.equals("")) {
                errorsig12 = 1;
                jLabel1.setForeground(new java.awt.Color(255, 0, 0));
            } else if (newsoft.equals("")) {
                errorsig12 = 1;
                jLabel2.setForeground(new java.awt.Color(0, 0, 0));
            } else if (newproc.equals("")) {
                errorsig12 = 1;
                jLabel3.setForeground(new java.awt.Color(0, 0, 0));
            } else if (newdeb.equals("")) {
                errorsig12 = 1;
                jLabel4.setForeground(new java.awt.Color(0, 0, 0));
            if (errorsig12 == 0) {
                PreparedStatement ps = con.prepareStatement("insert into customer set cust_name = ?, software = ?, processor = ?, debit = ?");
                ps.setString(4, newdeb);
                ps.setString(3, newproc);
                ps.setString(2, newsoft);
                ps.setString(1, newcust);
                int rs = ps.executeUpdate();
        } catch (SQLException eg) {
            System.out.println("SQL Exception: " + eg.toString());
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Thank you very much.

How about the following?
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     import java.net.URL;
     import javax.xml.parsers.DocumentBuilder;
     import javax.xml.parsers.DocumentBuilderFactory;
     import org.w3c.dom.Document;
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          DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
          DocumentBuilder db = dbf.newDocumentBuilder();
          URL url = new URL("http://foo.com/file.xml");
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My problem is that when I read the files, I believe that something is being corrupted - either by the internal workings of LabVIEW or something in my program. In particular, I notice that when I attempt to use the "Write to Binary File" vi something is being added to the file that I had not intended. At the beginning of the file I notice the string of characters " @" being added. I know that the analyzer is not giving me these characters so I suspect that LabVIEW is adding them somehow.
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Attachments:
4395A_SaveFile.jpg ‏2287 KB

Changing the extension of a bitmap file to get around the prohibition of posting them, is really inappropriate behavior. Use paint to save them as either jpg or png.
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Dear all,
We have a requirement where we have to upload data to FTP location in XML files, and then read from this into our database daily 2-3 times a day.
We have oracle 11g database, can someone kindly guide me how we can acheive this.
Also is there any tool for this? my management is thinking of purchasing one if it exists.
thank you

user10243788 wrote:
Thank you miheal,
is there any tool also we can use?The person I turn to for ideas about XML going into and out of the database is Marco Gralike.
Here's a sample (a couple of years old now) from his blog of mixing XML and SQL: http://www.liberidu.com/blog/2010/07/29/external-views-xml-based/
It's the first one I happened to get to when I did a search on his blog for: external table.
Some time back he sent me an example of running an SQL statement from the database which accessed the internet and pulled back the content of one of my blog pages in a form that would allow me to do: "insert into table select from {XML call}"
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Jonathan Lewis

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I am from Java Desktop Application background. May I know what is the best practice in J2EE, to atomic read and write a field in database. Currently, here is what I did
// In Servlet.
synchronized(private_static_final_object)
    int counter = read_counter_from_database();
    counter++;
    write_counter_back_to_database(counter);
}However, I suspect the above method will work all the time.
As my observation is that, if I have several web request at the same time, I am executing code within single instance of servlet, using different thread. The above method shall work, as different thread web request, are all referring to same "private_static_final_object"
However, my guess is "single instance of servlet" is not guarantee. As after some time span, the previous instance of servlet may destroy, with another new instance of servlet being created.
I also came across [http://code.google.com/appengine/docs/java/datastore/transactions.html|http://code.google.com/appengine/docs/java/datastore/transactions.html] in JDO. I am not sure whether they are going to solve the problem.
// In Servlet.
Transaction tx = pm.currentTransaction();
tx.begin();
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tx.commit();Is the code guarantee only when Thread A finish execute Line 1 till Line 3 atomically, only Thread B can continue to execute Line 1 till Line 3 atomically?
As I do not wish the following situation happen.
(1) Thread A read counter from Database as 0
(2) Thread A increment counter to 1
(3) Thread B read counter from Database as 0
(4) Thread A write counter as 1 to database
(5) Thread B increment counter to 1
(6) Thread B write counter as 1 to database
What I wish is
(1) Thread A read counter from Database as 0
(2) Thread A increment counter to 1
(4) Thread A write counter as 1 to database
(3) Thread B read counter from Database as 1
(5) Thread B increment counter to 2
(6) Thread B write counter as 2 to database
Thanks you.
Edited by: yccheok on Oct 27, 2009 8:39 PM

This is my understanding of the issue (you should research it further on you own to get a better understanding):
I suggest you use local variables (ie, defined within a function), and keep away from static variables. Those local variables are thread safe. If you call functions within functions, its still thread safe. If you read or write to one record in a database using sql, its thread safe (you dont need a transaction). If you read/write to multiple tables and/or records, you probably need a transaction. Servlets are thread safe. You usually dont need the 'synchronized' word anywhere unless you have a function updating/reading a static variable and therefore want to ensure only one user is accessing the static varible at a time. Also do so if you are writing to some resource (such as a file, a variable in applicaton scope, session scope, or resource that everyone uses such as email server). You dont want more than one person at a time to write to it). Note the database is one of of those resources that is handled by transactions rather than the the synchronized keyword (the synchronized keyword is applied to your application only (not other applications that someone is running), whereas the transaction ensures all applications are locked out while you update those records in the database).
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As title said, I try to use Mysql database with forte.
I read the manual , it said I have to put the database jdbc driver in
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Could you please give me some advices that I can fix this problem ?
Thanks in advance.
Ken @ Taipei , Taiwan , Asia

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