This chapter provides an example on how to drop an existing Database
using JDBC application. Before executing the following example, make
sure you have the following in place −
- To execute the following example you need to replace the username and password with your actual user name and password.
- Your MySQL or whatever database you are using is up and running.
Required Steps
The following steps are required to create a new Database using JDBC application −- Import the packages: Requires that you include the packages containing the JDBC classes needed for database programming. Most often, using import java.sql.* will suffice.
- Register the JDBC driver: Requires that you initialize a driver so you can open a communications channel with the database.
- Open a connection: Requires using the DriverManager.getConnection() method to create a Connection object, which represents a physical connection with a database server.
Deleting a database does not require database name to be in your database URL. Following example would delete STUDENTS database. - Execute a query: Requires using an object of type Statement for building and submitting an SQL statement to delete the database.
- Clean up the environment: Requires explicitly closing all database resources versus relying on the JVM's garbage collection.
Sample Code
Copy and paste the following example in JDBCExample.java, compile and run as follows −//STEP 1. Import required packages import java.sql.*; public class JDBCExample { // JDBC driver name and database URL static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; static final String DB_URL = "jdbc:mysql://localhost/"; // Database credentials static final String USER = "username"; static final String PASS = "password"; public static void main(String[] args) { Connection conn = null; Statement stmt = null; try{ //STEP 2: Register JDBC driver Class.forName("com.mysql.jdbc.Driver"); //STEP 3: Open a connection System.out.println("Connecting to a selected database..."); conn = DriverManager.getConnection(DB_URL, USER, PASS); System.out.println("Connected database successfully..."); //STEP 4: Execute a query System.out.println("Deleting database..."); stmt = conn.createStatement(); String sql = "DROP DATABASE STUDENTS"; stmt.executeUpdate(sql); System.out.println("Database deleted successfully..."); }catch(SQLException se){ //Handle errors for JDBC se.printStackTrace(); }catch(Exception e){ //Handle errors for Class.forName e.printStackTrace(); }finally{ //finally block used to close resources try{ if(stmt!=null) conn.close(); }catch(SQLException se){ }// do nothing try{ if(conn!=null) conn.close(); }catch(SQLException se){ se.printStackTrace(); }//end finally try }//end try System.out.println("Goodbye!"); }//end main }//end JDBCExampleNow, let us compile the above example as follows −
C:\>javac JDBCExample.java C:\>When you run JDBCExample, it produces the following result −
C:\>java JDBCExample Connecting to a selected database... Connected database successfully... Deleting database... Database deleted successfully... Goodbye! C:\>
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