JDBC Delete Database

This chapter provides examples on how to use JDBC applications to delete existing databases. Before executing the following examples, please ensure that you have the following conditions:

• To execute the following example, you need to replaceUsernameAndPasswordReplace it with the actual username and password.

• Your MySQL or any database you are using has already been started and is running.

NOTE: This is a serious operation, you must make a firm decision before continuing to delete the database, because all the content in the database will be lost.

Necessary steps

To create a new database using a JDBC application, you need to perform the following steps-

• Import package:You are required to include the software package that contains the JDBC classes required for database programming. Usually, useimport java.sql.*That's enough.

• Register the JDBC driver: You are required to initialize the driver so that you can open the communication channel with the database.

• You need to use the DriverManager.getConnection () method to create a Connection object that represents a physical connection to the database server.

  It is not necessary to include the database name in the database URL when deleting a database. The following example will deleteSTUDENTSDatabase.

• Execute query:You need to use an object of the Statement type to generate and submit SQL statements to delete the database.

• Clean up environment: All database resources must be explicitly closed instead of relying on JVM garbage collection.

Sample code

Copy and paste the following example into JDBCExample.java, compile and run as follows-

//Step1Import the 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{
　　　　　　//Step2Register JDBC driver
　　　　　　Class.forName("com.mysql.jdbc.Driver");
　　　　　　//Step3Establish connection
　　　　　　System.out.println("Connecting to a selected database...");
　　　　　　conn = DriverManager.getConnection(DB_URL, USER, PASS);
　　　　　　System.out.println("Connected database successfully...");
　　　　　　
　　　　　　//Step4Execute 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){
　　　　　　//Handling JDBC error
　　　　　　se.printStackTrace();
　　　}
　　　　　　//Handling Class.forName error
　　　　　　e.printStackTrace();
　　　}
　　　　　　//Used for closing resources
　　　　　　try{
　　　　　　　　　if(stmt!=null)
　　　　　　　　　　　　conn.close();
　　　　　　catch(SQLException se){
　　　　　　}//　Nothing to do
　　　　　　try{
　　　　　　　　　if(conn!=null)
　　　　　　　　　　　　conn.close();
　　　　　　catch(SQLException se){
　　　　　　　　　se.printStackTrace();
　　　　　　}
　　　}//End try
　　　System.out.println("Goodbye!");
}//End main
}//End JDBCExample

Now, let's compile the above example as follows:

C:\>javac JDBCExample.java
C:\>

RuntimeJDBCExampleIt will produce the following result-

C:\>java JDBCExample
Connecting to a selected database...
Database connected successfully...
Deleting database...
Database deleted successfully...
Goodbye!
C:\>