JDBC CONNECTION IN JAVA

DataBase_Connection.java

USING DATABASE COONECTION AS GLOBAL TO ALL PACKAGE:

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

public class DataBase_Connection

{

    private static final String USERNAME="root",PASSWORD="root",DRIVER="com.mysql.jdbc.Driver",

                          URL="jdbc:mysql://localhost/hotel";

    public Connection ConnectionGet() throws ClassNotFoundException, SQLException

    {

        Class.forName((DRIVER));

        Connection con=DriverManager.getConnection(URL, USERNAME,PASSWORD);

        return con;

        

        

    }

    

}

CALLING  DataBase_Connection.java IN NATIVE CODE:

INSERT QUERY:

Statement stm=new DatabaseConnection().ConnectionGet().createStatement();

stm.executeUpdate("insert into nutri(id,date) values("+maxid+",'"+dt+"')");

UPDATE QUERY:

Statement stm=new DatabaseConnection().ConnectionGet().createStatement();

 stm.executeUpdate("update nutri set "+colu+"='"+foodt+"' where id="+id+"");
JOptionPane.showMessageDialog(rootPane, colu+".. INSERTED FOR DATE...."+dt);

SELECT QUERY:
Statement stm=new DatabaseConnection().ConnectionGet().createStatement();
        ResultSet rs=stm.executeQuery("select * from nutri where id=(select max(id) from nutri)");
        while(rs.next())
                {
                    id=rs.getInt("id");
                    date=rs.getString("DATE").trim();
                          
                }

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SIMPLE JDBC CONNECTION WITHOUT SEPERATE CLASS USING MY SQL:

SIMPLE DATA INSERTION WITH STRING STARTS WITH CHAR “-“:

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public void datainsert() throws IOException

{

     Date dt=new Date();

       int maxid=0;

        try {

               String pattern = "dd/MM/yyyy";

               String pattern2="HH:mm:ss";

    SimpleDateFormat format = new SimpleDateFormat(pattern);

       String da=format.format(dt);

         SimpleDateFormat format2 = new SimpleDateFormat(pattern2);

         String tm=format2.format(dt);

        Class.forName("com.mysql.jdbc.Driver");

         Connection con= DriverManager.getConnection("Jdbc:mysql://localhost/stat","root","root");

        Statement stm=con.createStatement();

       ResultSet rs= stm.executeQuery("select max(id) from status");

       while(rs.next())

       {

          

            maxid=rs.getInt(1);

           

           

       }

       maxid+=1;

       String data=jPasswordField1.getText().trim();

       if(data.startsWith("-"))

       {

       stm.executeUpdate("insert into status values('"+maxid+"','"+da+"','"+tm+"','"+categ+data+"')");

      // JOptionPane.showMessageDialog(rootPane, "DATA ADDED");

      

       jPasswordField1.setText("");

       }

       else

       {

           throw new IOException("SYSTEM ERROR");

       }

        jButton1.setVisible(false);

       

        con.close();

        categ="$";

       

        }

       catch (SQLException | IOException |ClassNotFoundException e)

       {

           JOptionPane.showMessageDialog(rootPane, e.getMessage());

        }

      

}