package com.student.database;

// Import Statements

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;

public class DatabaseOperation // A class to perform all the database Operations {

static final String DbDriver   = "com.mysql.jdbc.Driver";  // To set the driver

static final String strConnection    = "jdbc:mysql://localhost:3306/student"; // Connection string 

static final String strDbUsername = "root"; // Username of the database user

static final String strDbPassword = "root"; // Password of the database user

static Connection   DatabaseConnection; // Connection object to establish the connectin to the database

static ResultSet    RsStudent; // Resultset to store the information retrieved from the database

static Statement    DatabaseStatement; // Statement object of the database connection

public DatabaseOperation () // Constructor of the class
{
    makeConnection(); // To establish the database connection
}

public void makeConnection() // To establish the database connection, No return value and parameters
{
    try
    {
        Class.forName(DbDriver); // Setting the driver

        DatabaseConnection = DriverManager.getConnection(strConnection, strDbUsername, strDbPassword); // Establishing the connection with the database

        DatabaseStatement = DatabaseConnection.createStatement(); // Assigning the statement to the connection
        System.out.println("Connection Success....");
    }
    catch (Exception e) // In case of any Exception
    {
        System.out.println(e); // Print the Exception
    }
}

public void insertIntoDatabase(String strInsertQuery) // A function which inserts the datavalues into the databases, No return value, Query as Parameter
{
    boolean IsResult = false; // To test whether the record is inserted

    try
    {
        IsResult = DatabaseStatement.execute(strInsertQuery); // Execute the insert Query

        //DatabaseConnection.commit(); // Commit
    }
    catch (Exception e)
    {
        System.out.println(e); // Incase of any error print the error
    }
}

public void updataDatabase(String strUpdateQuery) // A function which updates the changes into the database, No return type, Query as parameter
{
    try
    {
        int row = DatabaseStatement.executeUpdate(strUpdateQuery); // Returns No of rows affected
    }
    catch (Exception e)
    {
        System.out.println(e); // In case of errors, print the error
    }
}

public ResultSet selectFromDatabase(String strSelectQuery) // A function which retrieves Records from the database, Returns Recordset, Query as parameter
{
    try
    {
        RsStudent = DatabaseStatement.executeQuery(strSelectQuery); // Execute the select query
        return RsStudent; // Returns the resultset
    }
    catch (Exception e)
    {
        System.out.println(e); // Print the exception
        return null; // Return NULL
    }
}

public void deleteFromDB(String strDeleteQuery) // A function Which is used to execute delete Queries, No Return type, Query as Argument
{
    boolean IsReturn = false; // To check Whether the Query is appropriately Executed
    try
    {
        IsReturn = DatabaseStatement.execute(strDeleteQuery); // Executing the Query
    }
    catch (Exception e)
    {
        System.out.println(e); // Incase of Error, Print the error
    }
}

public void disConnect() {
    try {
        DatabaseConnection.close();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    // TODO Auto-generated method stub

}
public static void main(String[] args) {
    DatabaseOperation db = new DatabaseOperation();
    db.makeConnection();
}

}