PHP101 – การทำงานกับฐานข้อมูล MySQL เบื้องต้น

<?php

  $servername = "localhost"; // หรือ IP Address ของ Server
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  // สร้าง Connection
  $conn = new mysqli($servername, $username, $password, $dbname);

  // ตรวจสอบ Connection
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }
  echo "Connected successfully";

  $conn->close(); // ปิด Connection เมื่อใช้งานเสร็จ

?>

<?php
  // ... (สร้าง Connection) ...
  $conn->close();
?>

<?php

  $servername = "localhost";
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  $sql = "SELECT id, firstname, lastname FROM users";
  $result = $conn->query($sql);

  if ($result->num_rows > 0) {
    // แสดงข้อมูลแต่ละ Row
    while ($row = $result->fetch_assoc()) {
      echo "ID: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
    }
  } else {
    echo "0 results";
  }
  $conn->close();

?>

<?php

  $servername = "localhost";
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  $sql = "INSERT INTO users (firstname, lastname, email) VALUES ('John', 'Doe', 'john.doe@example.com')";

  if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
  } else {
    echo "Error: " . $sql . "<br>" . $conn->error;
  }

  $conn->close();

?>

<?php

  $servername = "localhost";
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  $sql = "UPDATE users SET lastname='Smith' WHERE id=1";

  if ($conn->query($sql) === TRUE) {
    echo "Record updated successfully";
  } else {
    echo "Error updating record: " . $conn->error;
  }

  $conn->close();

?>

<?php

  $servername = "localhost";
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  $sql = "DELETE FROM users WHERE id=1";

  if ($conn->query($sql) === TRUE) {
    echo "Record deleted successfully";
  } else {
    echo "Error deleting record: " . $conn->error;
  }

  $conn->close();

?>

<?php

  $servername = "localhost";
  $username = "your_username";
  $password = "your_password";
  $dbname = "your_database";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  // Prepared statement
  $stmt = $conn->prepare("SELECT id, firstname, lastname FROM users WHERE firstname = ? AND lastname = ?");
  $stmt->bind_param("ss", $firstname, $lastname); // "ss" หมายถึง parameter สองตัวเป็น String

  // กำหนดค่า parameter และ execute
  $firstname = "John";
  $lastname = "Doe";
  $stmt->execute();
  $result = $stmt->get_result();

  if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
      echo "ID: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
    }
  } else {
    echo "0 results";
  }

  $stmt->close();
  $conn->close();

?>