为什么我不能运行两个mysqli查询？第二个失败

Question

是否可以像这样有两个mysqli查询？

mysqli_query($dblink, "INSERT INTO images (project_id, user_id, image_name, date_created, link_to_file, link_to_thumbnail, given_name) VALUES ('$project_id', '$user_id', '$image_name', '$date_created', '$link_to_file', '$thumbnail', '$ImageName')");
mysqli_query($dblink, "INSERT INTO images_history (project_id, user_id, image_name, date_created, link_to_file, link_to_thumbnail, given_name, day, month, year) VALUES ('$project_id', '$user_id', '$image_name', '$date_created', '$link_to_file', '$thumbnail', '$ImageName', '$day', '$month', '$year')");

基本上，我想更新数据库中的两个表。有一个更好的方法吗？

Answer 1

可以使用mysqli_multi_query（）。

例：

<?php

$mysqli = new mysqli($host, $user, $password, $database);

// create string of queries separated by ;
$query  = "INSERT INTO images (project_id, user_id, image_name, date_created, link_to_file, link_to_thumbnail, given_name) VALUES ('$project_id', '$user_id', '$image_name', '$date_created', '$link_to_file', '$thumbnail', '$ImageName');";
$query .= "INSERT INTO images_history (project_id, user_id, image_name, date_created, link_to_file, link_to_thumbnail, given_name, day, month, year) VALUES ('$project_id', '$user_id', '$image_name', '$date_created', '$link_to_file', '$thumbnail', '$ImageName', '$day', '$month', '$year');";

// execute query - $result is false if the first query failed
$result = mysqli_multi_query($mysqli, $query);

if ($result) {
    do {
        // grab the result of the next query
        if (($result = mysqli_store_result($mysqli)) === false && mysqli_error($mysqli) != '') {
            echo "Query failed: " . mysqli_error($mysqli);
        }
    } while (mysqli_more_results($mysqli) && mysqli_next_result($mysqli)); // while there are more results
} else {
    echo "First query failed..." . mysqli_error($mysqli);
}

关键是如果要在单个调用中执行多个查询，则 必须
使用mysqli_multi_query。出于安全原因，mysqli_query将不执行多个查询以防止SQL注入。

还请记住的行为mysqli_store_result。它返回FALSE如果查询没有结果集（这INSERT查询不），所以你还必须检查mysqli_error地看到，它返回一个空字符串意味着INSERT成功。