PHP連接資料庫Mysql用mysqli連接 20240624
打開一個到 MySQL 伺服器的新連接<語法>mysqli_connect(host, username, password, dbname, port, socket);
- mysqli_connect_error()：連結錯誤訊息
- die()：中止腳本執行函數
- mysqli_close()：終止連線
<?php $servername = "localhost"; $username = "admin"; $password = "123456";
$conn = mysqli_connect($servername, $username, $password);
if(!$conn) { die("Connection failed: " . mysqli_connect_error()); } echo "Connected successfully!";
mysqli_close($conn);?>
改變默認連接的資料庫<語法>mysqli_select_db(connection, dbname)<?php mysqli_select_db($conn, $dbname) or die("Connect database failed: " . mysqli_error($conn));?>
連線成功後，加入mysqli_query($conn, "SET NAMES UTF8");，解決中文亂碼問題dbtools.inc.php<?php$servername = "localhost";$username = "admin";$password = "123456";$conn = mysqli_connect($servername, $username, $password);function create_connection(){ if(!$conn) { die("Connected fail: " . mysqli_connect_error()); } mysqli_query($conn, "SET NAMES UTF8"); return $conn;}function execute_sql($conn, $dbname, $sql) { mysqli_select_db($conn, $dbname) or die("Connect database failed: " . mysqli_error($conn)); $result = mysqli_query($conn, $sql); return $result;}?>使用require_once(" ");，引入需要的檔案select-use-dbtools.php<?phprequire_once("dbtools.inc.php");$conn = create_connection();$dbname = "db1";$sql = "SELECT * FROM db1";$result = execute_sql($conn, $dbname, $sql);// 判斷資料集內是否有資料if (mysqli_num_rows($result) > 0) { // 印出每列資料 while($row = mysqli_fetch_assoc($result)) { echo "ID: " . $row["ID"] . ";" . "Name: " . $row["Name"] . ";" . "Old: " . $row["Old"] . ";" . "Addr: " . $row["Addr"] . "<br />"; }} else { echo "0 results";}?>