Knowledge Sharing » MySQL

After Oracle Bought Sun

Dagu — Fri, 24 Apr 2009 09:46:14 +0000

Sun - Oracle

A few days ago, Oracle, a company which is known by it’s RDBMS, Oracle Database, bought Sun Microsystems ($7.4 billion.. wheewwww), a company which is known by it’s famous programming language, Java. As we know, Sun had bought MySQL, the famous open source database. Hmm… can you imagine how big Oracle now?

I just wonder what will happen tomorrow. Oracle has the enterprice market, meanwhile MySQL has SOHO market. Now Oracle has them all. I think Microsoft will be jealous. Microsoft SQL Server will not rule the Database World. Absolutely.

There are so many opinions about the future after Oracle bought Sun. May be Oracle will stop MySQL development, or still developing but not provide it as open source anymore. Or it will be better, MySQL will have Oracle features. What about Java? Do we have to pay to use Java like Microsoft does? Some people think it will be disaster. But I hope that Oracle won’t let open source community down.

Joomla Database Crash

Dagu — Sun, 22 Mar 2009 02:36:16 +0000

jtablesession::Store Failed
DB function failed with error number 145
Table ‘./joomla_database/jos_session’ is marked as crashed and should be repaired SQL=INSERT INTO `jos_session` (`session_id`,`time`,`username`,`gid`,`guest`,`client_id`) VALUES (’1ecb458814b53d190db10cafee822dc0′,’1237429551′,”’0′,’1′,’0′);

Error message above usually happens to CMS Joomla. One of Joomla tables jos_session (the table name depends on prefix) is crash. Don’t worry if you experience this problem. It’s easy to overcome this problem. Just truncate the table jos_session. SQL command:

mysql> truncate jos_session;

It’s done!

Creating Database in MySQL

Dagu — Thu, 08 Jan 2009 04:42:10 +0000

There are a few ways to create a database (known as schema) in MySQL, such as using command line or third party software.

Using Command Line
If we decide to use command line, then we must know the syntax to create it. It’s pretty simple: CREATE DATABASE database_name. Of course we should have a MySQL account which has privilege to create a database.

Example:

mysql> CREATE DATABASE dagunetdb;

Don’t forget the semicolon, then press Enter. It’s Done.

Using PHPMyAdmin
PHPMyAdmin is a web-based application which is used to manage databases. PHPMyAdmin is written in PHP Language. It can be downloaded here. Don’t worry, it’s free of charge. To create a database, you need to login to PHPMyAdmin (You need MySQL account which has privilege to create a database). In the front page, there is a text box to fill the database name. If you have typed it, click Create button. It’s done.

Create database using PHPMyAdmin

Using MySQL Query Browser
PHPMyAdmin is a web-based application, but MySQL Query Browser is desktop-based application. This software is developed by mysql.com. And it’s free also. Download MySQL Query Browser here. To create a database is as simple as pressing Ctrl + N. Type database name in pop-up window. Click OK. It’s done.

Creating Database Using MySQL Query Browser

Java & MySQL Connection

Dagu — Sat, 24 Nov 2007 04:18:00 +0000

To connect a Java application with MySQL, we need a driver as interface between Java and MySQL. Driver can be downloaded from the official MySQL website.

[ Download MySQL Connector ]

Extract downloaded file (file type: *.jar). Copy that file to directory [jre installation]/lib/ext/. Ok, your Java application is ready to connect with MySQL.

Testing
Code below is used to connect between Java and MySQL.
/*
* DBConnection.java
*
* Created on 29 September 2007, 11:41
*
*/

import java.sql.*;

/**
*
* @author Dani Gunawan
*/
public class DBConnection {

/** Creates a new instance of DBConnection */
public DBConnection() {
}

public Connection connect() {
Connection conn = null;

try
{
String userName = “root”;
String password = “”;
String url = “jdbc:mysql://blog.danigunawan.com/test”;
Class.forName (“com.mysql.jdbc.Driver”).newInstance ();
conn = DriverManager.getConnection (url, userName, password);
} catch (Exception e) {
e.printStackTrace();
conn = null;
} finally {
if (conn != null)
{
try
{
conn.close ();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
}

return conn;
}
}

Code below is used to test the database connection.

/**
* TesConnection.java
*/
import java.sql.*;

public class TesConnection {

public static void main(String args[]) {

Connection dbcon = new DBConnection().connect();

if (dbcon != null) {
System.out.println(“Database connection is successfully created”);
} else {
System.out.println(“Database connection isn’t successfully created”);
}
}

}

How to Use Them?
Put those two source in the same directory. Compile DBConnection.java and TesConnection.java respectively.

javac DBConnection.java
javac TesConnection.java

If you want to compile all of them, use wildcard asterisk (*).

javac *.java

Run TesConnection:

java TesConnection

If the result:

Database connection is successfully created

Then your database is has been connected. But if:

Database connection isn’t successfully created

means your Java application isn’t connected yet with the database.
Possibility:
- MySQL isn’t installed yet
- Database hasn’t been created yet (or maybe wrong database name)
- Wrong database user or password

Both source can be downloaded from link below:

[ Download example file ]

P.S.:
Code had been tested in Windows XP SP 2 Operating System, never been done in other operating systems.