Wordpress $wpdb->get_results 和 num_rows
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Wordpress $wpdb->get_results and num_rows
提问by Jimmyt1988
I'm using the following code:
我正在使用以下代码：
$wpdb->get_results("
SELECT * FROM " . $wpdb->prefix . "product_order
WHERE
rel = '" . $post["id"] . "' AND
`range` = '" . $range . "' AND
category = '" . $range . "'
");
echo $wpdb->num_rows;
num_rows returns 1 even though there is no rows in the database? Any ideas?
即使数据库中没有行，num_rows 也返回 1？有任何想法吗？
The variables I am putting in look fine. so it should be querying correctly.
我放入的变量看起来不错。所以它应该正确查询。
回答by Raman Singh
global $wpdb;
$wpdb->get_results("
SELECT * FROM " . $wpdb->prefix . "product_order
WHERE
rel = '" . $post["id"] . "' AND
`range` = '" . $range . "' AND
category = '" . $range . "'
");
echo $wpdb->num_rows;
Now it returns numbers of rows select from above query and 0 if no row selected.....
现在它返回从上面查询中选择的行数，如果没有选择行，则返回 0.....
回答by Scotty G
if you JUST want the count (maybe for pagination total), it is faster to do:
如果你只是想要计数（也许是分页总数），这样做会更快：
global $wpdb;
$rows = $wpdb->get_results("
SELECT COUNT(*) as num_rows FROM " . $wpdb->prefix . "product_order
WHERE
rel = '" . $post["id"] . "' AND
`range` = '" . $range . "' AND
category = '" . $range . "'
");
echo $rows[0]->num_rows;
