sql

package SQLiteHandler;

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

public class SqlHandler {
    //connection
    public static void connect(String db){
        Connection conn = null;
        try{
        String url="jdbc:sqlite:"+db+".sqlite";
        conn = DriverManager.getConnection(url);
        System.out.println("connection established");
        }catch(SQLException e){
            System.out.println(e.getMessage());
        }finally{
            try{
                if(conn != null){
                    conn.close();
                }
            }catch(SQLException e1){
                System.out.println(e1.getMessage());
            }
        }

    }
    public static void createNewTable(String db){
        String url="jdbc:sqlite:"+db+".sqlite";
        Connection conn = null;
        String sql="CREATE  TABLE \"main\".\"Providers\" (\"Id\" INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL  UNIQUE , "
                + "\"Name\" CHAR NOT NULL , "
                        + "\"Date\" DATETIME NOT NULL  DEFAULT CURRENT_DATE)";
    try{
        conn = DriverManager.getConnection(url);
        Statement stmt = conn.createStatement();
        stmt.execute(sql);
        System.out.println("table created succesfully");
    }catch(SQLException e){
        System.out.println(e.getMessage());
    }finally{
        try{
            if(conn != null){
                conn.close();
                }
        }catch(SQLException e1){
            System.out.println(e1.getMessage());
            }
        }
    }

    public static void insertData(String db,String tbl,String nm,String dt){
        String url="jdbc:sqlite:"+db+".sqlite";
        Connection conn = null;
        String sql= "INSERT INTO \"main\"."+tbl+" (\"Name\",\"Date\") VALUES (?1,?2)";
        try{
            conn = DriverManager.getConnection(url);
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, nm);
            pstmt.setString(2, dt);
            pstmt.executeUpdate();
            System.out.println("Inserted succesfully");
        }catch(SQLException e){
            System.out.println(e.getMessage());
        }finally{
            try{
                if(conn != null){
                    conn.close();
                    }
            }catch(SQLException e1){
                System.out.println(e1.getMessage());
                }
            }
    }

    public static void deleteTable(String db){
        String url="jdbc:sqlite:"+db+".sqlite";
        Connection conn = null;
        String sql="DROP TABLE \"CLIENTS\"";

    try{
        conn = DriverManager.getConnection(url);
        Statement stmt = conn.createStatement();
        stmt.execute(sql);
        System.out.println("table deleted succesfully");
    }catch(SQLException e){
        System.out.println(e.getMessage());
    }finally{
        try{
            if(conn != null){
                conn.close();
                }
        }catch(SQLException e1){
            System.out.println(e1.getMessage());
            }
        }
    }
    public static void deleteColumn(String db){
        String url="jdbc:sqlite:"+db+".sqlite";
        Connection conn = null;
        String sql="DELETE FROM PROVIDERS WHERE Name = Thanos ";
    try{
        conn = DriverManager.getConnection(url);
        Statement stmt = conn.createStatement();
        stmt.execute(sql);
        System.out.println("column deleted succesfully");
    }catch(SQLException e){
        System.out.println(e.getMessage());
    }finally{
        try{
            if(conn != null){
                conn.close();
                }
        }catch(SQLException e1){
            System.out.println(e1.getMessage());
            }
        }
    }

}