Are you sure you didn’t mean $wpdb->staff? By ommitting the $, the query now looks for a table called wpdb->staff, which isn’t valid SQL As an aside, had you considered using a custom post type/user meta instead of a custom table? Or even a custom taxonomy on users? Note as well that if you never … Read more
I found a post on Stack Overflow advising that converting a column from blob to text should result in no data loss. I didn’t really care about data loss since I wanted to remove the plugin data anyway, so I gave it a shot. On the Structure tab in phpMyAdmin, I edited the val column … Read more
You have a double quoted string, so your table name literally contains .’my_employees’ Try the curly syntax instead: “SELECT * FROM {$wpdb->prefix}my_employees WHERE ID = 1 “;
Your MySQL table structure creates a reference and constraint relationship between your wp_product table and wp_posts. MySQL is doing exactly what you have instructed it to do. In this case, preventing you from deleting a record in wp_posts that is ‘related’ to records in your wp_product table. In a nutshell, this is what foreign keys … Read more
This code is working for me with no “WordPress database error” messages: if ( $wpdb->get_var( $wpdb->prepare( “SHOW TABLES LIKE %s”, $table_name ) ) === $table_name ) { error_log( ‘Table exists’ . ‘: ‘ . print_r( $table_name, true ) ); } else { error_log( ‘Table does not exist’ . ‘: ‘ . print_r( $table_name, true ) … Read more
Well, since I haven’t used a LIKE in a plugin in a while, it seems I missed this one. WP is now adding ‘placeholders’ whenever you prepare or esc a query. The short solution I found was to do this. It may not be the proper one, but it works. $sql = $wpdb->remove_placeholder_escape($wpdb->prepare(“SELECT ID FROM … Read more
mysql_fetch_object() was deprecated in PHP 5.5 and fully removed in PHP 7.0, which is probably why it no longer works for you. It’s always better to use WP functions – often they are wrappers for something in PHP (or elsewhere), but by using the WP wrapper version, it usually protects you from deprecation (since the … Read more
Try wp_posts instead of wp_post.
PHP only runs when you request a page. When the request is over, everything is gone. It’s not like a Node application where the same program handles all the requests and variables can persist across pages just by defining them, so doing things with a $wp_session variable will only do things on that request. If … Read more
Replace the prefix in wp_users and wp_usermeta table names for the one you use. Make backup of data from both tables before you start to delete users. DELETE u FROM wp_users u LEFT JOIN wp_usermeta um1 ON u.id = um1.user_id AND um1.meta_key = ‘first_name’ LEFT JOIN wp_usermeta um2 ON u.id = um2.user_id AND um2.meta_key = … Read more