php pdo 基本操作

1. 不使用参数绑定：

<?php

try {
    $pdo = new PDO('mysql:host=localhost;dbname=laravel;charset:utf8', 'root', 'root');
    $pdo -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo 'database established successfully!' . '<br>';

    $sql1 = 'insert into colors set en = "asdf", zh_cn = "qwer"';
    $affectRows = $pdo -> exec($sql1);
    echo "successfully affect ${affectRows} line(s)" . '<br>';

    
    $sql2 = 'select * from colors;';
    $result = $pdo->query($sql2);

    $result_array = $result -> fetchAll();

    $count = count($result_array);

    echo "total ${count} rows " . PHP_EOL;

    foreach ($result_array as $item)
        print_r($item);

    
} catch (PDOException $e) {
    echo $e -> getMessage();
}

2. 使用参数绑定：

<?php

try {
    $pdo = new PDO('mysql:host=localhost;dbname=laravel;charset:utf8', 'root', 'root');
    $pdo -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo 'database established successfully!' . PHP_EOL;

    $sql1 = 'insert into colors set en = :en, zh_cn = :zh_cn';
    $stmt1 = $pdo -> prepare($sql1); 
    $stmt1 -> execute(['en' => 'zzz', 'zh_cn' => 'aaa']);

    $insert_rows = $stmt1 -> rowCount();

    echo $insert_rows . ' rows are created.' . PHP_EOL;
    

    $sql2 = "delete from colors where id >= :id";
    $stmt2 = $pdo->prepare($sql2);
    $stmt2 -> execute(['id' => 20]);
    $deleted_rows = $stmt2 -> rowCount();

    echo $deleted_rows . ' rows are deleted.' . PHP_EOL;


    $sql3 = "select * from colors where id < :id";
    $stmt3 = $pdo->prepare($sql3);
    $stmt3 -> execute(['id' => 3]);
    $queried_rows = $stmt3 -> rowCount();

    echo $queried_rows . ' rows are queried.' . PHP_EOL;
    

    foreach ($stmt3 as $row)
        print_r($row) . '<br>';

} catch (PDOException $e) {
    echo $e -> getMessage();
}