Question

更新我使用了以下查询：

$act1 = $dbh->prepare("(SELECT Title, start_date FROM service_o ORDER BY start_date DESC limit 2) UNION (SELECT Title, Start_Date FROM research_o ORDER BY start_date DESC limit 2) UNION (SELECT Title, Start_Date FROM intern_o ORDER BY start_date DESC limit 2) UNION (SELECT Title, Start_Date FROM participate_o ORDER BY start_date DESC limit 2)");

$act1->execute();
$act1->fetchAll();
$result = $act1->fetchall(PDO::FETCH_ASSOC);

是否绝对有必要使用var_dump？此外，我在使用它时得到一个未定义的偏移错误：

echo $result[0]['Title']

Answer 1

使用execute，然后使用fetchAll将所有结果作为数组返回。

$act1 = $dbh->prepare("SELECT  Title, start_date FROM table1 ORDER BY start_date DESC limit 2 
    UNION
    SELECT  Title, Start_Date FROM research_o ORDER BY table2 DESC limit 2 
    UNION
    SELECT  Title, Start_Date FROM intern_o ORDER BY table3 DESC limit 2 
    UNION
    SELECT  Title, Start_Date FROM participate_o ORDER BY table4 DESC limit 2 ");

$act1->execute();
$result = $act1->fetchAll(PDO::FETCH_ASSOC);

var_dump($result);

您的数组将采用如下结构：

$result = [
 '0' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '1' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '2' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '3' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '4' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '5' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '6' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
 '7' => [ 'Title' => 'some title', 'Start_Date' => '2009-10-15'],
];

这意味着您可以通过调用：

来访问面板中数组的每个元素

echo $result[0]['Title'] . ' - ' . $result[0]['Start_Date'];

或者，如果您想循环浏览它们并立即显示所有内容：

foreach ($result as $row) {
    echo '<div class="panel">' . $row['Title'] . ' - ' . $row['Start_Date'] . '</div>';
}

详细了解execute此处显示的内容，以便从查询中获取数据：http://php.net/manual/en/mysqli-stmt.execute.php

执行先前使用mysqli_prepare（）函数准备的查询。

如何在我的网页上的不同位置显示查询记录？

1 个答案: