数据库备份

在做具体的修改以前，建议先备份数据库，phpMyAdmin备份步骤如下：

• Login to your phpMyAdmin.
• Select your WordPress database.
• Click on Export at the top of the navigation.
• Select the tables you want to backup, or select all tables to backup the whole database.
• Select SQL to export as .sql extension.
• Check the "Save as file" checkbox.
• Choose compression type, select gzipped to compress the database to a smaller size.
• Finally click Go, and a download window will prompt you to save your backup database file.

实用SQL语句

变更博客网址 Siteurl & Homeurl

UPDATE wp_options SET option_value = replace(option_value, 'http://www.oldsiteurl.com', 'http://www.newsiteurl.com') WHERE option_name = 'home' OR option_name = 'siteurl';

变更博文归属GUID

UPDATE wp_posts SET guid = REPLACE (guid, 'http://www.oldsiteurl.com', 'http://www.newsiteurl.com');

变更博文中的URL引用

UPDATE wp_posts SET post_content = REPLACE (post_content, 'http://www.oldsiteurl.com', 'http://www.newsiteurl.com');

变更博文中的图片加载引用

UPDATE wp_posts SET post_content = REPLACE (post_content, 'src="http://www.oldsiteurl.com', 'src="http://yourcdn.newsiteurl.com');
UPDATE wp_posts SET guid = REPLACE (guid, 'http://www.oldsiteurl.com', 'http://yourcdn.newsiteurl.com') WHERE post_type = 'attachment';

变更博文Meta信息中的URL引用

UPDATE wp_postmeta SET meta_value = REPLACE (meta_value, 'http://www.oldsiteurl.com','http://www.newsiteurl.com');

变更默认的管理员"Admin"用户名

UPDATE wp_users SET user_login = 'Your New Username' WHERE user_login = 'Admin';

密码重置

UPDATE wp_users SET user_pass = MD5( 'new_password' ) WHERE user_login = 'your-username';

变更博文归属（从作者B到作者A）

首先需要获得两个作者的ID，可以通过管理员面板来浏览作者的详细信息，此时查看浏览器地址栏中的链接，寻找"user_id=?"

UPDATE wp_posts SET post_author = 'new-author-id' WHERE post_author = 'old-author-id';

删除博文修订记录

DELETE a,b,c FROM wp_posts a
LEFT JOIN wp_term_relationships b ON (a.ID = b.object_id)
LEFT JOIN wp_postmeta c ON (a.ID = c.post_id)
WHERE a.post_type = 'revision'

删除博文指定的Meta信息

DELETE FROM wp_postmeta WHERE meta_key = 'your-meta-key';

收集评论的Email地址

SELECT DISTINCT comment_author_email FROM wp_comments;

删除博文的Pingback

DELETE FROM wp_comments WHERE comment_type = 'pingback';

删除所有的垃圾评论

• 0 = Comment Awaiting Moderation
• 1 = Approved Comment
• spam = Comment marked as Spam

DELETE FROM wp_comments WHERE comment_approved = 'spam';

删除没有使用的Tags

SELECT * From wp_terms wt
INNER JOIN wp_term_taxonomy wtt ON wt.term_id=wtt.term_id WHERE wtt.taxonomy='post_tag' AND wtt.count=0;

参照文章

• 13 Useful WordPress SQL Queries You Wish You Knew Earlier

WordPress中实用的SQl语句，首发于润物无声。