[英]PHP PDO Fetch returns 0 results when including certain columns
我正在创建与数据库的连接,调用fetch并在json中回显我的结果; 但是,当我将某些列包括在select语句中时...什么也没回来。
这是我的代码的样子:
$data = array();
$page = 0;
$perPage = 30;
$offset = $page * $perPage;
$query = "SELECT wp.ID,
REPLACE(wp.post_title, 'Episode - ','') AS header,
CASE WHEN img.guid IS NULL THEN meta_img.meta_value ELSE img.guid END AS image_url,
wp.post_excerpt AS about, **INCLUDING THIS**
lessons.meta_value as lessons, **OR THIS**
title.meta_value AS detail **OR THIS. BRINGS BACK NO RESULTS**
FROM wp_posts wp
INNER JOIN wp_postmeta title on title.post_id = wp.id and title.meta_key = 'academy_title'
INNER JOIN wp_postmeta lessons on lessons.post_id = wp.id and lessons.meta_key = 'academy_lessons'
LEFT JOIN wp_postmeta meta_img on meta_img.post_id = wp.id and meta_img.meta_key = 'image'
LEFT JOIN wp_postmeta meta on meta.post_id = wp.id and meta.meta_key = '_thumbnail_id'
LEFT JOIN wp_posts img on img.id = meta.meta_value
WHERE wp.post_title LIKE 'Episode%' AND wp.post_status = 'publish'
ORDER BY wp.post_date DESC
LIMIT $offset, $perPage";
$result = $this->db->query($query);
while ($row = $result->fetch()) {
$data[] = $row;
}
echo json_encode($data);
我知道我的连接工作正常,因为其他更简单的查询也可以工作,但是由于某种原因,当我在查询中包括最后3列(about, lessons, detail)
,结果什么也没带回来……这没有任何意义。
我对此很陌生,所以我认为可能不接受某些语法? 但事实是,它不返回基本列的结果,而不返回具有实际逻辑的结果...
编辑:
在对字段进行SUBSTR(wp.post_excerpt, 1, 4) as about
并限制其大小时...有效。 我该如何解决?
检查phpAdmin或其他上的查询,并确保这些列存在并且写得很好。
更新尝试
$data = array();
while ($row = $result->fetch()) {
$data[] = $row;
}
更新2可能存在关于编码,特殊字符的问题,诸如此类
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