Working with DML and DDL using NetBeans IDE

In the previous sections, I explained how to work with “PreparedStatements” in Java.  Now, we shall discuss issuing DDL statements such as CREATE, ALTER, and so on.

Let us work with a new form in the same application.  Within the “Projects” view, open “Source Packages,” right-click on “MyDBPack,” and go to “new->JFrame form” (Fig03).  I currently named it “DBSample08.” Make sure that you change the code behind it to the following:

public DBSample08() {
        initComponents();
        this.setSize(300,200);
    }

You design the form exactly as in previous sections. Copy the following code into the “Button click” event (or “ActionPerformed” event):

private void btnConnectActionPerformed(java.awt.event.ActionEvent
evt) {                                          

// TODO add your handling code here:
        try {
           Class.forName
("com.microsoft.jdbc.sqlserver.SQLServerDriver");          
            Connection conn = DriverManager.getConnection
("jdbc:microsoft:sqlserver://serverjag:1433","sa","");
            Statement sql_stmt = conn.createStatement();
            sql_stmt.execute("CREATE TABLE Northwind..dept
(deptno int, dname varchar(20), loc int);");
            sql_stmt.close();
            conn.close();
            this.txtMsg.setText("created table successfully");
        }
        catch(Exception e) {
            this.txtMsg.setText("Error: Please view Stack
Trace");
            e.printStackTrace();
        }
    }             

In the above code, instead of using “executeQuery” or “executeUpdate,” I used simply “execute.”  The “executeQuery” returns a “ResultSet” object from which we need to extract information. The DML statement does not return any “ResultSet.”  To work with “DDL” statements, it is better to use the “execute” method.

Even though I demonstrated a simple CREATE TABLE in the above example, you can replace the same with other DDL statements such as ALTER TABLE, DROP TABLE, and so forth.

To modify the “start-up” form before execution, you can follow the instructions in my previous article.  Once you complete the “start-up” form configuration, you can press F5 to execute, and you should be able to see your new form.

Remarks

The entire code for this article is freely available in the form of a zip file.  That downloadable solution was developed using NetBeans 4.1 IDE and tested with Microsoft SQL Server 2000 database Enterprise Edition (with Service Pack 3).  I didn’t really test it in any other version.  If you are unable to connect to the respective database, please post in the discussion section, so that I may guide you.

I used Microsoft Windows 2003 Standard Edition to work with this sample.  I request that you follow the steps according to the operating system installed on your computer. Most of them will be very similar and very easy to understand (unless it is a different platform).

The final point you should know is that none of my articles in this series are optimized for performance. Tuning/improving the performance of a Java application is beyond the scope of this article.  I simply wanted to explain the concepts a bit more clearly. 

Any doubts, bugs, errors, suggestions, feedback etc. are highly appreciated at jag_chat@yahoo.com.