//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/EMP";
// Database credentials
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
try{
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL,USER,PASS);
//STEP 4: Execute a query to create statment with
// required arguments for RS example.
System.out.println("Creating statement...");
Statement stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
//STEP 5: Execute a query
String sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
System.out.println("List result set for reference....");
printRs(rs);
//STEP 6: Loop through result set and add 5 in age
//Move to BFR postion so while-loop works properly
rs.beforeFirst();
//STEP 7: Extract data from result set
while(rs.next()){
//Retrieve by column name
int newAge = rs.getInt("age") + 5;
rs.updateDouble( "age", newAge );
rs.updateRow();
}
System.out.println("List result set showing new ages...");
printRs(rs);
// Insert a record into the table.
//Move to insert row and add column data with updateXXX()
System.out.println("Inserting a new record...");
rs.moveToInsertRow();
rs.updateInt("id",104);
rs.updateString("first","John");
rs.updateString("last","Paul");
rs.updateInt("age",40);
//Commit row
rs.insertRow();
System.out.println("List result set showing new set...");
printRs(rs);
// Delete second record from the table.
// Set position to second record first
rs.absolute( 2 );
System.out.println("List the record before deleting...");
//Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
//Delete row
rs.deleteRow();
System.out.println("List result set after \
deleting one records...");
printRs(rs);
//STEP 8: Clean-up environment
rs.close();
stmt.close();
conn.close();
}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(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye!");
}//end main
public static void printRs(ResultSet rs) throws SQLException{
//Ensure we start with first row
rs.beforeFirst();
while(rs.next()){
//Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
System.out.println();
}//end printRs()
}//end JDBCExample
