mysql - Read For Learn

How to extract and reveal code from SQL database in WordPress

Count views without get_post_meta

If you provided full code, issue is probably in this line: $wpdb->prepare(“INSERT INTO ‘myprefix_posts_views’ (postid, ip, device) VALUES (%d, %s, %s) ON DUPLICATE KEY UPDATE create_at=VALUES(create_at)”, $postID, $_SERVER[‘REMOTE_ADDR’], $_SERVER[‘HTTP_USER_AGENT’]); Because into column postid you are trying to put variable $postID, when you didn’t declare it anywhere. This column is NOT NULL, so probably you have … Read more

WordPress Post Query Using Custom native MySQL like St_Distance_Sphere

WordPress User Login not accepted although listed in DB

How to return count number from a wordpress database

It is recommended to use the $wpdb->get_var() method when retrieving a count of rows. This method will return the count directly, rather than inside of an array or object like wpdb::get_results().

Naming conventions for database tables

There’s only one naming convention to remember, the WP table prefix. If you don’t want to use it you can do whatever you want. WordPress only cares about its own tables, you can create any other tables you want. Keep in mind though that the WordPress table prefix isn’t always wp_, and it changes for … Read more

SQL errors when querying for something with apostrophes

Using the wpdb::prepare() method is recommended for creating queries properly and avoiding SQL injection. For a basic solution, use the addslashes() function, but this is not sufficient for preventing SQL injection. See Mysql + php with special characters like ‘(Apostrophe) and ” (Quotation mark).