在 JDBC 上使用键盘插入数据时出错

Question

In JDBC, I want to insert data using input from the keyboard.

As a result of finding the method, I came to know the scanner and wrote the code as follows.

package DB;

import java.sql.SQLException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.util.Scanner;

class insert{

    Connection con;

    Statement stmt;

    Scanner scan = new Scanner(Syetem.in);

    public insert() {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            String url = "jdbc:oracle:thin:@localhost:1521:orcl";
            con = DriverManager.getConnection(url,"scott","1234");
            stmt = con.createStatement();
        } catch(ClassNotFoundException ce) {
            System.out.println(ce.getMessage());
        } catch(SQLException se){
            System.out.println(se.getMessage());
        }
    }

    public void disconnect() throws SQLException{
        if (stmt!=null) stmt.close();
        if (con!=null) con.close();
    }

    public void insert() throws SQLException{
        System.out.println("name:")
        String employee_name=scan.next();

        System.out.println("domain:")
        String street=scan.next();

        System.out.println("country:")
        String city=scan.next();

        String sql="insert into information values('"+name+"', '"+domain+"', '"+country+"')";

        int n=stmt.executeUpdate(sql);
    }

}

But it didn't run and got an error... The default method cannot be found in the class. Define a default method in the following format. public static void main (String [] args)

Where should I put the main function to fix the error?

What is the problem? The name of the table to be inserted is 'information'.

Any help would be greatly appreciated

• Because JDBC is not yet familiar, if possible, if you write a full query including a connection as in the above query, I would be very grateful.

*my oracle version is 11g

Answer 1

For your code to run you need to provide a method that works as an entry point for your program, that method has the signature public static void main(String[] args) besides that, your class should be named Insert with capital I first because thats de standard y second because you have a method called insert, you will need to have something like this:

public class Insert {
  public Insert() { 
  ...    
  }

  public void disconnect() throws SQLException {
  ...
  }

  public void insert() throws SQLException {
  ...
  }

  public static void main(String[] args) {
    new Insert().insert();
  }
}