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Simple Java Program to Acess books database.

Write a simple java program to access the books database and display all the contents in the authors table.(Install MySql and the MySql-JDBC connector)
Heres the code I have but its for DIFFERENT TABLES. can you please correct the code for program to access the books database and display all the contents in the authors table

1	// Fig. 25.25: DisplayAuthors.java
	2	// Displaying the contents of the authors table.
	3	import java.sql.Connection;
	4	import java.sql.Statement;
	5	import java.sql.DriverManager;
	6	import java.sql.ResultSet;
	7	import java.sql.ResultSetMetaData;
	8	import java.sql.SQLException;
	9	
	10	public class DisplayAuthors 
	11	{
	12	   // JDBC driver name and database URL                              
	13	   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";        
	14	   static final String DATABASE_URL = "jdbc:mysql://localhost/books";
	15	   
	16	   // launch the application
	17	   public static void main( String args[] )
	18	   {
	19	      Connection connection = null; // manages connection
	20	      Statement statement = null; // query statement
	21	    
	22	      // connect to database books and query database
	23	      try 
	24	      {
	25	         Class.forName( JDBC_DRIVER ); // load database driver class
	26	
	27	         // establish connection to database                              
	28	         connection =                                                     
	29	            DriverManager.getConnection( DATABASE_URL, "jhtp6", "jhtp6" );
	30	
	31	         // create Statement for querying database
	32	         statement = connection.createStatement();
	33	         
	34	         // query database                                        
	35	         ResultSet resultSet = statement.executeQuery(            
	36	            "SELECT authorID, firstName, lastName FROM authors" );
	37	         
	38	         // process query results
	39	         ResultSetMetaData metaData = resultSet.getMetaData();
	40	         int numberOfColumns = metaData.getColumnCount();     
	41	         System.out.println( "Authors Table of Books Database:" );
	42	         
	43	         for ( int i = 1; i <= numberOfColumns; i++ )
	44	            System.out.printf( "%-8s\t", metaData.getColumnName( i ) );
	45	         System.out.println();
	46	         
	47	         while ( resultSet.next() ) 
	48	         {
	49	            for ( int i = 1; i <= numberOfColumns; i++ )
	50	               System.out.printf( "%-8s\t", resultSet.getObject( i ) );
	51	            System.out.println();
	52	         } // end while
	53	      }  // end try
	54	      catch ( SQLException sqlException )                                
	55	      {                                                                  
	56	         sqlException.printStackTrace();
	57	         System.exit( 1 );                                               
	58	      } // end catch

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Gibu George

This code looks ok.

>Heres the code I have but its for DIFFERENT TABLES
What does this mean?

Gibu George

One thing once the statement and rs are used close it. do that in the finally block and similarly once you are done with the connection object close that also

durrr

ASKER

I just got the Code from Deitel and Deitel Text Book but I was NOT sure if this code is right one for QUESTION i have posed. Can you please recheck if the answer to my question is the code I have incorporated. I thought that the code is attached is for different query with different connection. Can you please re-check it thoroughly and tell me if this is the right code for my question. Thanks

Gibu George

The code which you have posted connects to a mysql db, gets the authorid, firstname,lastname from the authors table (all the rows). and dynamically goes through the result set and prints the authorid, firstname and last name row by row.

If you are having different tables, and connection details you just need to change the query. and the connection details like the url , user name, password.

Gibu George

if you want all the columns of the authors table
change the query to select * from authors, this also will work

durrr

ASKER

Can you please Change it and post the updated Code, I dont wanna mess it up. Please bear with my ignorance, I am very new to all this programming. Please make the changes and attach the file. Thank you Gibu.

Gibu George

please find the attached code snippet, i hope the tables name is authors

// 25.25: DisplayAuthors.java
// Displaying the contents of the authors table.
import java.sql.Connection;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
 
public class DisplayAuthors {
	// JDBC driver name and database URL
	static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
	static final String DATABASE_URL = "jdbc:mysql://localhost/books";
 
	// launch the application
	public static void main(String args[]) {
		Connection connection = null; // manages connection
		Statement statement = null; // query statement
 
		// connect to database books and query database
		try {
			Class.forName(JDBC_DRIVER); // load database driver class
 
			// establish connection to database
			connection = DriverManager.getConnection(DATABASE_URL, "jhtp6",
					"jhtp6");
 
			// create Statement for querying database
			statement = connection.createStatement();
 
			// query database
			ResultSet resultSet = statement
					.executeQuery("SELECT * FROM authors");
 
			// process query results
			ResultSetMetaData metaData = resultSet.getMetaData();
			int numberOfColumns = metaData.getColumnCount();
			System.out.println("Authors Table of Books Database:");
 
			for (int i = 1; i <= numberOfColumns; i++)
				System.out.printf("%-8s\t", metaData.getColumnName(i));
			System.out.println();
 
			while (resultSet.next()) {
				for (int i = 1; i <= numberOfColumns; i++)
					System.out.printf("%-8s\t", resultSet.getObject(i));
				System.out.println();
			} // end while
		} // end try
		catch (SQLException sqlException) {
			sqlException.printStackTrace();
			System.exit(1);
		} // end catch
		catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(connection!=null){
				try {
					connection.close();
				} catch (SQLException e) {
					connection=null;
				}
			}
		}
	}
}

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durrr

ASKER

Got my question answered. Thanks Gibu

ASKER CERTIFIED SOLUTION

Gibu George

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Gibu George

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