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[[oktatas:programozás:java:java adatbázis:mysql|< MySQL]]

====== Java MySQL - Kezdés ======

  * **Szerző:** Sallai András
  * Copyright (c) 2023, Sallai András
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]]
  * Web: https://szit.hu

===== A modell =====

<code java Employee.java>
import java.time.LocalDate;

public class Employee {
    Integer id;
    String name;
    String city;    
    double salary;
    LocalDate birth;
    public Employee(
            Integer id, 
            String name, 
            String city, 
            double salary, 
            LocalDate birth) {
        this.id = id;
        this.name = name;
        this.city = city;
        this.salary = salary;
        this.birth = birth;
    }    
}

</code>

===== Beszúrás =====

<code java Program01.java>
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.DriverManager;
import java.time.LocalDate;
 
class Program01 {
    public static void insertEmployee(Employee employee) {
        Connection conn = null;
        try {
            String url = "jdbc:mysql://localhost:3306/surubt";
            conn = DriverManager.getConnection(url, 
            "surubt", "titok");
 
            String sql = "insert into employees" +
                " (name, city, salary, birth) values" +
                " (?, ?, ?, ?)";        
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, employee.name);
            pstmt.setString(2, employee.city);
            pstmt.setDouble(3, employee.salary);
            pstmt.setDate(4, Date.valueOf(employee.birth));
            pstmt.execute();
 
 
        }catch(SQLException ex) {
            System.err.println("Hiba! Az SQL művelet sikertelen!");
            System.err.println(ex.getMessage());
        }
    }
    
    public static void main(String[] args) {
        Employee emp = new Employee(
            1, 
            "Csendes Emese", 
            "Szolnok", 
            345, 
            LocalDate.parse("2002-05-15")
            );
        insertEmployee(emp);
    }
}

</code>


===== Lekérdezés =====

<code java Program01.java>
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.DriverManager;
import java.util.ArrayList;
 
class Program01 {
    public static ArrayList<Employee> getEmployees() {
        ArrayList<Employee> employeeList = new ArrayList<>();
        Connection conn = null;
        try {
            String url = "jdbc:mysql://localhost:3306/surubt";
            conn = DriverManager.getConnection(url, 
            "surubt", "titok");
 
            String sql = "select * from employees";        
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            while(rs.next()) {
                Employee emp = new Employee(
                    rs.getInt("id"),
                    rs.getString("name"),
                    rs.getString("city"),
                    rs.getDouble("salary"),
                    rs.getDate("birth").toLocalDate()
                    );
                employeeList.add(emp);
            }
 
 
        }catch(SQLException ex) {
            System.err.println("Hiba! Az SQL művelet sikertelen!");
            System.err.println(ex.getMessage());
        }
        return employeeList;
    }
    
    public static void main(String[] args) {
        ArrayList<Employee> employeeList;
        employeeList = getEmployees();
        employeeList.forEach(emp -> {
            System.out.println(emp.name);
        });
    }
}

</code>