java mysql的增删改查

String url = "jdbc:mysql://localhost:3306/mydatabase";
String user = "username";
String password = "password";

try (Connection conn = DriverManager.getConnection(url, user, password)) {
    String sql = "INSERT INTO users (name, email) VALUES (?, ?)";
    try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
        pstmt.setString(1, "John Doe");
        pstmt.setString(2, "john.doe@example.com");
        pstmt.executeUpdate();
    }
} catch (SQLException e) {
    e.printStackTrace();
}

String sql = "DELETE FROM users WHERE id = ?";
try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
    pstmt.setInt(1, 1); // 假设我们要删除id为1的用户
    pstmt.executeUpdate();
} catch (SQLException e) {
    e.printStackTrace();
}

String sql = "UPDATE users SET email = ? WHERE id = ?";
try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
    pstmt.setString(1, "new.email@example.com");
    pstmt.setInt(2, 1); // 假设我们要更新id为1的用户邮箱
    pstmt.executeUpdate();
} catch (SQLException e) {
    e.printStackTrace();
}

String sql = "SELECT * FROM users";
try (Statement stmt = conn.createStatement();
     ResultSet rs = stmt.executeQuery(sql)) {
    while (rs.next()) {
        int id = rs.getInt("id");
        String name = rs.getString("name");
        String email = rs.getString("email");
        System.out.println("ID: " + id + ", Name: " + name + ", Email: " + email);
    }
} catch (SQLException e) {
    e.printStackTrace();
}