This article, written to accord with WordPress 2.9, is now obsolete. Please take caution when following its contents, as many things may have changed.

The following is an outline and description of the database tables created during the standard installation of WordPress Version 2.9. At the time, the only database supported by WordPress Version 2.9 was MySQL version 4.1.2 or greater.

Also see prior versions of Database Descriptions for WordPress 1.5, WordPress 2.0, WordPress 2.2, WordPress 2.3, WordPress 2.5, WordPress 2.7, and WordPress 2.8.

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 to interface with 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 (WP Version 2.5+) created during the WordPress standard installation. The Table Overview below includes additional details on the tables and columns.

(WP 2.5 Database diagram)

[An updated diagram for version 2.9.1 can be found here.]

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.

Table Name	Description	Relevant Area(s) of WordPress User Interface
WordPress 2.9 Tables (11)
wp_commentmeta	Each comment features information called the meta data and it is stored in the `wp_commentmeta`.	Typically plugins would be add their own information to this table.
wp_comments	The comments within WordPress are stored in the `wp_comments` table.	Comments are created by readers as responses to posts. Comments are managed by administrator via 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 > Edit
wp_options	The Options set under the Administration > Settings panel are stored in the `wp_options` table.	Administration > Settings > General Administration > Settings > Writing Administration > Settings > Reading Administration > Settings > Discussion Administration > Settings > Privacy Administration > Settings > Permalinks Administration > Settings > Miscellaneous 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.	Administration > Posts > Add New Administration > Posts > Edit Administration > Pages > Add New Administration > Pages > Edit Administration > Media > Add New Administration > Media > Library
wp_terms	The categories for both posts and links and the tags for posts are found within the `wp_terms` table.	Administration > Posts > Tags Administration > Posts > Categories Administration > Links > Link Categories Administration > Posts > Add New Administration > Posts > Edit Administration > Pages > Add New Administration > Page > Edit
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	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

Table: wp_links

Field	Type	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	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	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

Table: wp_terms

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

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	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	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

Resources

A look inside the WordPress database - an in-depth discussion of the database tables by Leonid Mamchenkov.

Changelog

2.9 :
- commentmeta table: New table to house comment related data.
- options table: Made keyname option_name UNIQUE.
- updated diagram

2.8 :
- comments table: Changed comment_post_ID column from int(11) to bigint(20) unsigned.
- links table: Deleted link_category column. Changed link_owner column from int(11) to bigint(20) unsigned.
- posts table: Deleted post_category column.
- term_taxonomy table: Added KEY taxonomy.
- Add unsigned attribute to various bigint(20) fields.

2.7 :
- term table: Changed name field varchar(55) -> varchar(200).
- Added KEY name to the term table.
- Added KEY post_parent to the posts table.

2.5 :
- All of enum type fields -> varchar(20):
  - comments table: comment_approved field
  - links table: link_visible
  - options table: autoload
  - posts table: post_status, comment_status, ping_status
- Added KEY comment_approved_date_gmt and comment_date_gmt to the comments table.
- Added term_order field to the term_relationships table
- see also: Migrating Plugins and Themes to 2.5 - Database changes

2.3 :
- Added the terms, term_taxonomy and term_relationships tables. Removed categories, link2cat and post2cat tables.
- Rremoved 6 fields from the options table. (option_can_override, option_type, option_width, option_height, option_description, and option_admin_level)
- Added new status 'pending' for post_status field to the posts table.
- see also: WordPress Taxonomy

2.1 :
- Removed the linkcategories table. linkcategories data were marged to the categories table, and IDs were reseted.
- Added post_type field to the posts table (in 2.0.x, post_status = 'static' for Pages)
- Added new status 'future' for post_status field to the posts table, instead of NOW() in 2.0.x.
- see also: Migrating Plugins and Themes to 2.1 - Core WordPress Database Changes

Codex

Database Description/2.9

Contents

Database Diagram

Table Overview

Table Details

Table: wp_commentmeta

Indexes

Table: wp_comments

Indexes

Table: wp_links

Indexes

Table: wp_options

Indexes

Table: wp_postmeta

Indexes

Table: wp_posts

Indexes

Table: wp_terms

Indexes

Table: wp_term_relationships

Indexes

Table: wp_term_taxonomy

Indexes

Table: wp_usermeta

Indexes

Table: wp_users

Indexes

Resources

Changelog

Codex Resources