WP Database Description

Database Description

The following is an outline and description of the database tables created during the standard installation of WordPress Version 3.0. Currently, the only database supported by WordPress is MySQL version 4.1.2 or greater.

 

Because WordPress interfaces with this database by itself, you as an end user, shouldn’t have to worry much about its structure. If you’re Writing a Plugin however, you may be interested in learning how WordPress stores its data and relationships. If you have already attempted to use the existing WordPress API to access the data you need but have determined it’s not possible without accessing the database directly, WordPress provides the wpdb class to make this task easy.

Database Diagram

The diagram below provides a visual overview of the WordPress database and the relations between the tables created during the WordPress standard installation. The Table Overview below includes additional details on the tables and columns.

Please note that within the standard installation of WordPress no integrity between the tables is enforced e.g. between posts and comments. If you are creating a plugin or extension that manipulates the WordPress database, your code should do the housekeeping so that no orphan records remain in the tables e.g. by removing records in other tables with a set of SQL commands when foreign keys are deleted (Don’t forget to remind users to backup before such operations).

Table Overview

This section is the overview of all the tables created during the WordPress standard installation. It is followed by specific information of what is in each table.

WordPress 3.0 Tables (11)
Table Name	Description	Relevant Area(s) of WordPress User Interface
wp_commentmeta	Each comment features information called the meta data and it is stored in the wp_commentmeta.	Administration > Comments > Comments
wp_comments	The comments within WordPress are stored in the wp_comments table.	Administration > Comments > Comments
wp_links	The wp_links holds information related to the links entered into the Links feature of WordPress.	Administration > Links > Add New Administration > Links > Links
wp_options	The Options set under the Administration > Settings panel are stored in the wp_options table. See Option Reference for option_name and default values.	Administration > Settings > General Administration > Settings > Writing Administration > Settings > Reading Administration > Settings > Discussion Administration > Settings > Privacy Administration > Settings > Permalinks Administration > Appearance > Widgets
wp_postmeta	Each post features information called the meta data and it is stored in the wp_postmeta. Some plugins may add their own information to this table.	Administration > Posts > Add New Administration > Pages > Add New
wp_posts	The core of the WordPress data is the posts. It is stored in the wp_posts table. Also Pages and navigation menu items are stored in this table.	Administration > Posts > Add New Administration > Posts > Posts Administration > Pages > Add New Administration > Pages > Pages Administration > Media > Add New Administration > Media > Library Administration > Appearance > Menus
wp_terms	The categories for both posts and links and the tags for posts are found within the wp_terms table.	Administration > Posts > Post Tags Administration > Posts > Categories Administration > Links > Link Categories Administration > Posts > Add New Administration > Posts > Posts Administration > Pages > Add New Administration > Page > Pages
wp_term_relationships	Posts are associated with categories and tags from the wp_terms table and this association is maintained in the wp_term_relationships table. The association of links to their respective categories are also kept in this table.
wp_term_taxonomy	This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.
wp_usermeta	Each user features information called the meta data and it is stored in wp_usermeta.	Administration > Users
wp_users	The list of users is maintained in table wp_users.	Administration > Users

Table Details

The following are the specific fields in each of the tables created during the standard WordPress installation.

Table: wp_commentmeta

Field	Type	Null	Key	Default	Extra
meta_id	bigint(20) unsigned		PRI	NULL	auto_increment
comment_id	bigint(20) unsigned		IND	0	FK->wp_comments.comment_id
meta_key	varchar(255)	YES	IND	NULL
meta_value	longtext	YES		NULL

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	0	meta_ID
comment_id	INDEX	none	comment_id
meta_key	INDEX	none	meta_key

Table: wp_comments

Field	Type	Null	Key	Default	Extra
comment_ID	bigint(20) unsigned		PRI	NULL	auto_increment
comment_post_ID	bigint(20) unsigned		IND	0	FK->wp_posts.ID
comment_author	tinytext
comment_author_email	varchar(100)
comment_author_url	varchar(200)
comment_author_IP	varchar(100)
comment_date	datetime			0000-00-00 00:00:00
comment_date_gmt	datetime		IND & IND Pt2	0000-00-00 00:00:00
comment_content	text
comment_karma	int(11)			0
comment_approved	varchar(20)		IND & Ind Pt1	1
comment_agent	varchar(255)
comment_type	varchar(20)
comment_parent	bigint(20) unsigned			0	FK->wp_comments.ID
user_id	bigint(20) unsigned			0	FK->wp_users.ID

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	1	comment_ID
comment_approved	INDEX	None	comment_approved
comment_post_ID	INDEX	None	comment_post_ID
comment_approved_date_gmt	INDEX	None	comment_approved comment_date_gmt
comment_date_gmt	INDEX	None	comment_date_gmt
comment_parent	INDEX	None	comment_parent

Table: wp_links

Field	Type	Null	Key	Default	Extra
link_id	bigint(20) unsigned		PRI	NULL	auto_increment
link_url	varchar(255)
link_name	varchar(255)
link_image	varchar(255)
link_target	varchar(25)
link_description	varchar(255)
link_visible	varchar(20)		IND	Y
link_owner	bigint(20) unsigned			1
link_rating	int(11)			0
link_updated	datetime			0000-00-00 00:00:00
link_rel	varchar(255)
link_notes	mediumtext
link_rss	varchar(255)

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	7	link_ID
link_category	INDEX	None	link_category
link_visible	INDEX	None	link_visible

Table: wp_options

Field	Type	Null	Key	Default	Extra
option_id	bigint(20) unsigned		PRI Pt1	NULL	auto_increment
blog_id	int(11)		PRI Pt2	0
option_name	varchar(64)		PRI Pt3 & IND
option_value	longtext
autoload	varchar(20)			yes

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	184	option_id blog_id option_name
option_name	UNIQUE	184	option_name

Table: wp_postmeta

Field	Type	Null	Key	Default	Extra
meta_id	bigint(20) unsigned		PRI	NULL	auto_increment
post_id	bigint(20) unsigned		IND	0	FK->wp_posts.ID
meta_key	varchar(255)	YES	IND	NULL
meta_value	longtext	YES		NULL

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	13	meta_ID
post_id	INDEX	15	post_id
meta_key	INDEX	7	meta_key

Table: wp_posts

Field	Type	Null	Key	Default	Extra
ID	bigint(20) unsigned		PRI & IND Pt4		auto_increment
post_author	bigint(20) unsigned			0	FK->wp_users.ID
post_date	datetime		IND Pt3	0000-00-00 00:00:00
post_date_gmt	datetime			0000-00-00 00:00:00
post_content	longtext
post_title	text
post_excerpt	text
post_status	varchar(20)		IND PT2	publish
comment_status	varchar(20)			open
ping_status	varchar(20)			open
post_password	varchar(20)
post_name	varchar(200)		IND
to_ping	text
pinged	text
post_modified	datetime			0000-00-00 00:00:00
post_modified_gmt	datetime			0000-00-00 00:00:00
post_content_filtered	text
post_parent	bigint(20) unsigned			0	FK->wp_posts.ID
guid	varchar(255)
menu_order	int(11)			0
post_type	varchar(20)		IND Pt1	post
post_mime_type	varchar(100)
comment_count	bigint(20)			0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	2	ID
post_name	INDEX	None	post_name
type_status_date	INDEX	None	post_type post_status post_date ID
post_parent	INDEX	None	post_parent
post_author	INDEX	None	post_author

Table: wp_terms

Field	Type	Null	Key	Default	Extra
term_id	bigint(20) unsigned		PRI		auto_increment
name	varchar(200)
slug	varchar(200)		UNI
term_group	bigint(10)			0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	2	term_ID
slug	UNIQUE	2	slug
name	Index	none	name

Table: wp_term_relationships

Field	Type	Null	Key	Default	Extra
object_id	bigint(20) unsigned		PRI Pt1	0
term_taxonomy_id	bigint(20) unsigned		PRI Pt2 & IND	0	FK->wp_term_taxonomy.term_taxonomy_id
term_order	int(11)			0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	8	object_id term_taxonomy_id
term_taxonomy_id	INDEX	None	term_taxonomy_id

Table: wp_term_taxonomy

Field	Type	Null	Key	Default	Extra
term_taxonomy_id	bigint(20) unsigned		PRI		auto_increment
term_id	bigint(20) unsigned		UNI Pt1	0	FK->wp_terms.term_id
taxonomy	varchar(32)		UNI Pt2
description	longtext
parent	bigint(20) unsigned			0
count	bigint(20)			0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	2	term_taxonomy_id
term_id_taxonomy	UNIQUE	2	term_id taxonomy
taxonomy	INDEX	None	taxonomy

Table: wp_usermeta

Field	Type	Null	Key	Default	Extra
umeta_id	bigint(20) unsigned		PRI	NULL	auto_increment
user_id	bigint(20) unsigned			‘0’	FK->wp_users.ID
meta_key	varchar(255)	Yes	IND	NULL
meta_value	longtext	Yes	IND	NULL

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	9	umeta_id
user_id	INDEX	None	user_id
meta_key	INDEX	None	meta_key

Table: wp_users

Field	Type	Null	Key	Default	Extra
ID	bigint(20) unsigned		PRI	NULL	auto_increment
user_login	varchar(60)		IND
user_pass	varchar(64)
user_nicename	varchar(50)		IND
user_email	varchar(100)
user_url	varchar(100)
user_registered	datetime			0000-00-00 00:00:00
user_activation_key	varchar(60)
user_status	int(11)			0
display_name	varchar(250)

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	1	ID
user_login_key	INDEX	None	user_login
user_nicename	INDEX	None	user_nicename

Multisite Table Overview

This section is the overview of the tables created for use with the Multisite feature of WordPress. These tables are created via the processes under Administration > Tools > Network.

These tables are considered the multisite global tables.

WordPress 3.0 Multisite Tables
Table Name	Description	Relevant Area(s) of WordPress User Interface
wp_blogs	Each site created is stored in the table, wp_blogs.	Administration > Tools > Network Administration > Super Admin > Sites
wp_blog_versions	The current database version status of each site is maintained in the wp_blogs_versions table and is updated as each site is upgraded.	Administration > Super Admin > Update
wp_registration_log	The wp_registration_log records the admin user created when each new site is created.	Administration > Super Admin > Sites
wp_signups	This table holds the user that have registered for a site via the login registration process. User registration is enable in Administration > Super Admin > Options.	Administration > Settings > General
wp_site	The wp_site table contains the main site address.	Administration > Tools > Network
wp_sitecategories	If global terms (global_terms_enabled = true) are enabled for a site the wp_sitecategories table holds those terms.	Administration > Super Admin > Options Administration > Posts > Add New
wp_sitemeta	Each site features information called the site data and it is stored in wp_sitemeta. Various option information, including the site admin is kept in this table.	Administration > Super Admin > Options
wp_users	The list of all users is maintained in table wp_users. Multisite add two fields not in the stand-alone version.	Administration > Users Administration > Super Admin > Users Administration > Super Admin > Sites – Edit Site
wp_usermeta	This table is not re-create for multisite, but meta data of users for each site are stored in wp_usermeta.	Administration > Users Administration > Super Admin > Users Administration > Super Admin > Sites – Edit Site
Site Specific Tables	The data of the main site are stored in existing unnumbered tables. The data of additional sites are stored in new numbered tables.	Administration > Super Admin > Sites – Add Site

Multisite Table Details

The following describe the tables and fields created during the network installation. Note that a global set of tables is created upon creation of the network, and site-specific tables are established as each site is created.

Table: wp_blogs

Field	Type	Null	Key	Default	Extra
blog_id	bigint(20) unsigned		PRI	NULL	auto_increment
site_id	bigint(20) unsigned		IND	0
domain	varchar(200)	NO		0
path	varchar(100)	NO
registered	datetime	NO		0000-00-00 00:00:00
last_updated	datetime	NO		0000-00-00 00:00:00
public	tinyint(2)	NO		0
archived	enum(‘0′,’1’)	NO		0
mature	tinyint(2)	NO		0
spam	tinyint(2)	NO		0
deleted	tinyint(2)	NO		0
lang_id	int(11)	NO		0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	2	blog_id
domain	INDEX	none	domain(50),path(5)
lang_id	INDEX	none	lang_id

Table: wp_blog_versions

Field	Type	Null	Key	Default	Extra
blog_id	bigint(20) unsigned		PRI	0	FK->wp_blogs.blog_id
db_version	varchar(20)	NO
last_updated	datetime	NO		0000-00-00 00:00:00

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	2	blog_id
db_version	INDEX	none	db_version

Table: wp_registration_log

Field	Type	Null	Key	Default	Extra
ID	bigint(20) unsigned		PRI	NULL	auto_increment
email	varchar(255)	NO
IP	varchar(30)	NO
blog_id	bigint(20) unsigned		PRI	0	FK->wp_blogs.blog_id
date_registered	datetime	NO		0000-00-00 00:00:00

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	1	ID
IP	INDEX	none	IP

Table: wp_signups

Field	Type	Null	Key	Default	Extra
domain	varchar(200)	NO		0
path	varchar(100)	NO
title	longtext	NO
user_login	varchar(60)	NO	IND
user_email	varchar(100)	NO
registered	datetime	NO		0000-00-00 00:00:00
activated	datetime	NO		0000-00-00 00:00:00
active	tinyint(1)	NO
activation_key	varchar(50)	NO
meta	longtext

Indexes

Keyname	Type	Cardinality	Field
activation_key	INDEX	None	activation_key
domain	INDEX	None	domain

Table: wp_site

Field	Type	Null	Key	Default	Extra
id	bigint(20) unsigned		PRI	NULL	auto_increment
domain	varchar(200)	NO		0
path	varchar(100)	NO

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	1	id
domain	INDEX	none	domain,path

Table: wp_sitecategories

Field	Type	Null	Key	Default	Extra
cat_id	bigint(20) unsigned	NO	PRI	NULL	auto_increment
cat_name	varchar(55)	NO
category_nicename	varchar(200)	NO
last_updated	timestamp	NO

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	9	cat_id
category_nicename	INDEX	None	category_nicename
last_updated	INDEX	None	last_updated

Table: wp_sitemeta

Field	Type	Null	Key	Default	Extra
meta_id	bigint(20) unsigned		PRI	NULL	auto_increment
site_id	bigint(20) unsigned			‘0’	FK->wp_site.site_id
meta_key	varchar(255)	Yes	IND	NULL
meta_value	longtext	Yes	IND	NULL

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	9	meta_id
meta_key	INDEX	None	meta_key
site_id	INDEX	None	site_id

Table: wp_users

Field	Type	Null	Key	Default	Extra
ID	bigint(20) unsigned		PRI	NULL	auto_increment
user_login	varchar(60)		IND
user_pass	varchar(64)
user_nicename	varchar(50)		IND
user_email	varchar(100)
user_url	varchar(100)
user_registered	datetime			0000-00-00 00:00:00
user_activation_key	varchar(60)
user_status	int(11)			0
display_name	varchar(250)
spam	tinyint(2)	NO		0
deleted	tinyint(2)	NO		0

Indexes

Keyname	Type	Cardinality	Field
PRIMARY	PRIMARY	1	ID
user_login_key	INDEX	None	user_login
user_nicename	INDEX	None	user_nicename

Site Specific Tables

When a new additional site is created, the site-specific tables, similar to the stand-alone tables above, are created. Each set of tables for a site are created with the site ID (blog_id) as part of the table name. These are the tables that would be created for site ID 2 and table_prefix wp_:

• wp_2_commentmeta
• wp_2_comments
• wp_2_links
• wp_2_options
• wp_2_postmeta
• wp_2_posts
• wp_2_terms
• wp_2_term_relationships
• wp_2_term_taxonomy

The data of the main site are stored in unnumbered tables.