This is essentially a SQL question. The only possible WordPress related component would be if you were asking about database structure, which is in the Codex. Or you could just look at the database itself. The post ID is incremented and never duplicated. The highest IDs are the last added. The query is simple. SELECT … Read more
Since: upgrade endpoint in question doesn’t seem to be behind login wall no user action is required other than visiting it I would imagine requesting the suggested URL with some CLI tool for HTTP requests (curl and wget are commonly available) should accomplish upgrade.
The behavior I described in my post only happens when you are using $wpdb->update to execute an UPDATE statement. If you want to update a different database using the same connection, use $wpdb->query to send a raw query, WP won’t modify it then.
wpdb is a simple wrapper around the mysql_* functions, but you can’t mix and match them. $wpdb->query does not return the database reference that mysql_fetch_row needs. It … … returns an integer corresponding to the number of rows affected/selected. If there is a MySQL error, the function will return FALSE. (Note: since both 0 and … Read more
Not a good idea to modify core WP files. Figure out the issue with the MySQL server dying: it’s going to be lack of good server configuration, a (very) bad quality host or a theme that is very database query-intensive. Fixing the underlying cause of the database server errors is the best thing to do … Read more
Yes you can have more than one database, this type of set-up is for large traffic heavy sites and you would want to use something like http://wordpress.org/plugins/hyperdb/ . This is outside the scope of the vast majority of WordPress sites. You can manage a multitude of blogs from 1 db if you want using http://codex.wordpress.org/Create_A_Network. … Read more
You need to activate the default theme in the admin; WordPress will just bail on the front-end if the active theme isn’t on the filesystem (it won’t fallback to the default automatically).
First of all your query is wrong. The right query is $mypost = $wpdb->query($wpdb->prepare(“SELECT post_content FROM $wpdb->posts WHERE ID = %d”, 2)); Second the $wpdb->query will returns an integer value indicating the number of rows affected/selected. You can check here http://codex.wordpress.org/Class_Reference/wpdb#General_Syntax If you want generic result you can use $wpdb->get_results http://codex.wordpress.org/Class_Reference/wpdb#SELECT_Generic_Results $mypost = $wpdb->get_results($wpdb->prepare(“SELECT post_content … Read more
wpdb doesn’t include such kind of API, mostly since it descended from ezSQL which didn’t either (as far as I remember). While there are some helpers for insert/update stuff, most of query abstraction happens in WP_Query since that’s where bulk of complicated querying is typically going on.
First off, you should not be handing an untrusted input (in this case, $_GET[‘id’] to your database. Always SQL-escape the query and validate/sanitize the data. (In the code snippet below, it’s SQL-escaped using $wpdb->prepare() for escaping and int typecasting to sanitize to integer value). Secondly, the $wpdb object provides more than just the query() function. … Read more