MySQL is an open-source, relational database management system.

learn more… | top users | synonyms

44
votes
6answers
45k views

Using wpdb to connect to a separate database

I want to connect wpdb to another database. How do I create the instance and pass it the database name/username/password? Thanks
31
votes
6answers
24k views

Why is my database import losing text widget data?

I've created a site in WordPress on our development machine. In the theme we're using there are numerous widget zones to display text in (sidebar and front page). I've used simple Text widgets in all ...
23
votes
4answers
23k views

MySQL Database User: Which Privileges are needed?

The short installation instruction for WordPress ("5 Minutes") state that: Create a database for WordPress on your web server, as well as a MySQL user who has all privileges for accessing and ...
16
votes
3answers
13k views

Should I use wpdb prepare?

I'm new to SQL and am wondering if I need to use wpdb->prepare for the following query to a table I've created global $wpdb; $tablename = $wpdb->prefix . "my_custom_table"; $sql = "SELECT * ...
12
votes
8answers
64k views

What SQL Query to do a simple find and replace

Whenever I create a new website I first create a staging site on a subdomain like "stage.domain-name.com". After everything works correctly I export the database, open it in notepad++ and do a ...
11
votes
2answers
4k views

The MySQL alternatives: Do Percona Server and MariaDB work well with WordPress, and do they make WordPress go better?

Lately I've been reading about MariaDB and Percona Server, two strong alternatives to MySQL that have gained popularity since Oracle bought Sun. As far as I know, both of them could be used with ...
10
votes
2answers
7k views

Wordpress Database Slow - should I switch to InnoDB?

I have a WordPress site with well over 10k posts, and things are starting to get very slow whenever I am adding and editing posts. Pages load nice and fast for users, along with the admin lists of ...
9
votes
3answers
15k views

How do you properly prepare a %LIKE% SQL statement?

I'd like to use a LIKE %text% statement while still using the WordPress $wpdb class to sanitize and prepare input. SELECT column_1 from `prefix_my_table` WHERE column_2 LIKE '%something%'; I've ...
9
votes
3answers
783 views

What's a good strategy for planning WordPress DB growth?

Hoping for some feedback on the topic of optimizing and staying on top of performance as a WordPress database grows... to paint a picture.... let's say you have a WordPress / Buddypress MU site that ...
9
votes
1answer
3k views

Why are simple updates to wp_postmeta's “_edit_lock” so slow?

In our MySQL slow query log, the cumulatively slowest query is a simple update to wp_postmeta. Here's an example: UPDATE `wp_postmeta` SET `meta_value` = '1392835505:386' WHERE `post_id` = 94705 ...
8
votes
8answers
15k views

How to replace the domain name in a Wordpress database?

I have a Wordpress database which was installed in a development environment... thus, all references to the site itself have a fixed IP address (say 192.168.16.2). Now, I have to migrate that database ...
8
votes
5answers
12k views

What are the recommended database permissions for WordPress?

I just got WP running on my own server. I am not trying to lock things down more. What permissions should the db user have to my WP db?
7
votes
4answers
5k views

the_date() not working

I am using wordpress 3.2 and I did a query post like this: <?php query_posts("posts_per_page=1post=type&page=post_parent=10");?> Then I try to echo out the date of this post I queried ...
7
votes
4answers
5k views

How can I find the source of slow queries in Wordpress?

I have a WordPress site with more than 8000 posts and everytime I add a new one the site becomes unresponsive. I checked the MySQL slow queries log and found out that it is performing a select that ...
7
votes
1answer
136 views

Reset Post IDs to less than 64bit integer

I have been running Wordpress for many years and have about 26000 posts. At some point my post ids have exceeded a 32bit integer and I am now locked into using Wordpress on a 64 bit system. I am ...
7
votes
1answer
924 views

dbDelta support for FOREIGN KEY

On PHP 5.3.13/MySQL 5.5.21 the following code doesn't work: if($check_custom_fields_form!=1){ $sql = "CREATE TABLE IF NOT EXISTS ". $table_custom_fields_form ." ( `form_name` ...
7
votes
1answer
203 views

How do I optimize a custom post type admin page with 25,000 posts?

I'm getting the occasional excessive resource limit error to due to loading so many posts at once. We had set the PHP limit to 128 but just loading the list of posts for a couple of the post types is ...
6
votes
2answers
407 views

WordPress database scalability from the code perspective

I have read through multiple questions here on StackExchange that concern WordPress scaling and the common opinion is that WordPress is indeed highly scalable provided you have the infrastructure to ...
6
votes
3answers
1k views

Resetting comment count

Recently, I had to move to another domain and had to recreate all my MySQL tables on the enw server. I noticed that for some posts, the number of comments is doubled. Example - ...
6
votes
2answers
6k views

WordPress mysqli and PDO

Does wordpress code base use mysqli or PDO? I know PDO is superior to mysqli but mysqli is not bad neither. Plus from one of the features of what makes PDO is superior to mysqli ( that is being ...
6
votes
2answers
6k views

Checking if Database Table exists

I read the wordpress codex and professional wordpress. It seems both use something like if($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) { to determine if the table exists. Is ...
6
votes
2answers
349 views

Optimize Wordpress Query that take 5 seconds to execute

I have a large wordpress database: rows in key tables: 730K wp_posts 404K wp_terms 752K wp_term_relationships 27K wp_term_taxonomy 1.8 Million wp_postmeta The issue is that I have a query ...
6
votes
3answers
7k views

is it possible to run some php code within a wordpress page?

I'd like to access a DB table and render it in some data grid format using php on a dedicated wordpress page, accessible to members of a certain group. Is this at all possible with wordpress or is ...
6
votes
3answers
3k views

Complex meta query with 3 keys

I think the problem essentially relates to sql query structure and I am not an expert.... I need to search for posts (custom post type) by 2 parameters: pd_city pd_country Please note that ...
6
votes
1answer
752 views

Would switching to InnoDB from MyISAM improve performance of comments table?

A site I've built gets lots of comments in a short space of time - so perhaps 100 comments might be left in 5 or 10 minutes. This seems to cause a pretty heavy load on the database, especially when ...
6
votes
1answer
381 views

Automatically delete inactive users after 2 months

I am trying to modify this function: // automatically delete users after 7 days in wordpress function wcs_auto_delete_users() { global $wpdb; $query = $wpdb->prepare( "SELECT ID FROM ...
5
votes
2answers
459 views

Lack of composite indexes for meta tables

Why wp_commentmeta table does not have a composite index (comment_id, meta_key) by default? I believe it's the only useful index for that table, am I wrong? Instead, it has a strange set of indexes: ...
5
votes
2answers
1k views

Can i use php sql functions instead of $wpdb?

I'm new to WordPress and was wondering why in WordPress API do they tell you to use functions such as prepare(), insert(), get_col(), get_row(), query(), etc. when technically I can use the built-in ...
5
votes
2answers
346 views

Is it possible to define two databases for one installation?

Is it possible to define 2 database for one wp installation, I have searched but there are options for one database and 2 installations. I want this because, one of my clients site is hosted on ...
5
votes
2answers
2k views

How to prevent execution of default query, while preserving ability to use WP_Query in template?

PROBLEM: I'am trying to prevent execution of default WordPress query for custom category template. I have found a possible solution, but looks like it preventing execution of all post queries: ...
5
votes
1answer
1k views

How does Wordpress handle MySQL row lock errors?

If there is a WordPress plugin which updates rows in a custom table, but that update encounters a row lock, what happens? E.g. two users simultaneously fire an update on TABLE1, one setting AGE=1 and ...
5
votes
1answer
890 views

How to run WordPress across 2 VMs for high availability

Microsoft Azure requires that applications utilize two instances across multiple data centers in order to achieve their "high availability" SLA and ensure your sites don't go down for routine ...
5
votes
2answers
423 views

Ordering posts by day (not time) AND meta value

I would like to have a list of posts that is first ordered by day, and then within that day ordered user votes (stored as a meta field). Would it be better to convert each timestamp to the day at ...
5
votes
2answers
772 views

Use REGEXP in WP_Query meta_query key

I know I can use REGEXP in WP_Query like this: $query = new WP_Query(array( 'posts_per_page' => -1, 'post_status' => 'publish', 'meta_query' => array( array( ...
5
votes
3answers
976 views

MySQL Replication Latency Issues in wp-admin pages

I have an environment running WP 3.0.1 with a Master db and two slaves. I am using HyperDB to force all writes to go to the Master, and all reads to read from the two slaves. I am experiencing a ...
5
votes
1answer
673 views

Slow wp_term_relationships query

I'm running a large WP instance (currently has 28,000+ posts in custom types) and have been experiencing some odd slowdowns. Upon analyzing the MySQL slow query log, one of the problem queries is: ...
4
votes
3answers
5k views

Retrieve featured image

We are building an Android app based on a Wordpress mysql database. We were able to get most of the information from the datase to display on to the app. Now all we have left is to retrieve the posts ...
4
votes
3answers
3k views

Optimize Multiple Taxonomy Term MySQL Query?

(Moderator's note: Title was originally: "query/database optimisation") I'm written a function for a custom "filter" search panel that allows users to select terms from up to four custom taxonomies. ...
4
votes
2answers
5k views

Get Previous & Next posts by Post ID

How can I go about getting the previous and next posts from outside the loop? Everything I try to do aside from the custom SELECT query (using get_posts or WP_Query) breaks stuff further down the ...
4
votes
5answers
14k views

Will it break my site if I delete all transient records in wp_options table?

My site currently has an outrageous 500k+ transient records in the wp_options table. This causes the table to be crashed frequently and so be my site. I thought transient records will all expired ...
4
votes
2answers
34k views

Connect to database using wordpress wp-config file

How can I connect to the database using the wp-config.php file ? I'm trying to make a script more Wordpress friendly, and I need to connect to the database, but without installing the script as a ...
4
votes
2answers
3k views

Get posts by menu ID

I'm a little stuck here. I have a menu in Wordpress with some posts in it. What I would like is to retrieve all the posts as objects. I think I'm pretty close, but the SQL query doesn't seem to work ...
4
votes
3answers
1k views

How to log mysql errors from wordpress core?

I am developing a wordpress site and I would like to be able to log and handle mysql errors from wordpress core. My site has a mix of wordpress pages and posts + a few php pages that run under the ...
4
votes
2answers
9k views

Where is the content of widgets stored in mysql table

I have the cPanel access to a website but no wordpress login info. So I wants to change a widget content in the website. How can I change it through phpmyadmin. Where are that widgets sidebar data ...
4
votes
1answer
56 views

How to define composite keys with dbDelta()

I am getting error while trying to create a table with dbDelta() and composite primary key. The sql is pretty straight forward. $sql = "CREATE TABLE {$wpdb->prefix}voicemail_call ( user_id ...
4
votes
2answers
1k views

WordPress use innodb by default?

I just created a new WordPress site in my server. Normally, WordPress uses MyISAM as the database type. But this time, it created all InnoDB tables! Is this normal? Has WordPress switched to InnoDB in ...
4
votes
2answers
2k views

Set page template for all pages?

I know the page template is set in the wpdb as meta_key = _wp_page_template and meta_value = template.php. How can I write a SQL script to set each post where post_type = 'page' to a specific ...
4
votes
1answer
1k views

Problems with DBDelta with FOREIGN key?

I have the following sql I am using with dbDelta: $sql .= "CREATE TABLE " . $location_table . " ( location_id MEDIUMINT(9) NOT NULL AUTO_INCREMENT, name VARCHAR (100), ...
4
votes
1answer
326 views

Custom query to get post names beginning with a digit

I'm implementing an A-Z index for a custom post type. I've got my links printing out the page and the query working for the letters. However, the numbers are tripping me up because I don't want them ...
4
votes
2answers
2k views

Searching users with WP_List_Table plug-in

I am trying to devlope a plugin that will search and return my users so I can edit some other metatdata that belongs to them. I have been using the plug-in listed on the Codex as my starting point. I ...