PHP MySQL 读取数据
从 MySQL 数据库读取数据
SELECT 语句用于从数据表中读取数据:
SELECT column_name(s) FROM table_name
以下实例中我们从表 MyGuests 读取了 id, firstname 和 lastname 列的数据并显示在页面上：
实例 (MySQLi - 面向对象)
<?php
$$servername = "localhost";
$$username = "username";
$$password = "password";
$$dbname = "myDB";
// 创建连接
$$conn = new mysqli($$servername, $$username, $$password, $$dbname);
// 检测连接
if ($$conn->connect_error) {
die("Connection failed: " . $$conn->connect_error);
}
$$sql = "SELECT id, firstname, lastname FROM MyGuests";
$$result = $$conn->query($$sql);
if ($$result->num_rows > 0) {
// 输出每行数据
while($$row = $$result->fetch_assoc()) {
echo "<br> id: ". $$row["id"]. " - Name: ". $$row["firstname"]. " " . $$row["lastname"];
}
} else {
echo "0 results";
}
$$conn->close();
?>
以下实例读取了 MyGuests 表的所有记录并显示在 HTML 表格中：
实例 (PDO)
<?php
echo "<table style='border: solid 1px black;'>";
echo "<tr><th>Id</th><th>Firstname</th><th>Lastname</th><th>Email</th><th>Reg date</th></tr>";
class TableRows extends RecursiveIteratorIterator {
function __construct($$it) {
parent::__construct($$it, self::LEAVES_ONLY);
}
function current() {
return "<td style='width: 150px; border: 1px solid black;'>" . parent::current(). "</td>";
}
function beginChildren() {
echo "<tr>";
}
function endChildren() {
echo "</tr>" . "\n";
}
}
$$servername = "localhost";
$$username = "username";
$$password = "password";
$$dbname = "myDBPDO";
try {
$$conn = new PDO("mysql:host=$$servername;dbname=$$dbname", $$username, $$password);
$$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$$stmt = $$conn->prepare("SELECT * FROM MyGuests");
$$stmt->execute();
// 设置结果集为关联数组
$$result = $$stmt->setFetchMode(PDO::FETCH_ASSOC);
foreach(new TableRows(new RecursiveArrayIterator($$stmt->fetchAll())) as $$k=>$$v) {
echo $$v;
}
$$dsn = null;
}
catch(PDOException $$e)
{
echo "Error: " . $$e->getMessage();
}
$$conn = null;
echo "</table>";
?>
