WordPressデータベースの接頭辞を変更してセキュリティを向上させる方法

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1. Dave van Hoorn

   Update the SQL for renaming the prefixes please. WordPress adds the ‘wp_termmeta’ table now. It’s included in the SQL below.

   RENAME table `wp_commentmeta` TO `wp_yoursitename_commentmeta`;
   RENAME table `wp_comments` TO `wp_yoursitename_comments`;
   RENAME table `wp_links` TO `wp_yoursitename_links`;
   RENAME table `wp_options` TO `wp_yoursitename_options`;
   RENAME table `wp_postmeta` TO `wp_yoursitename_postmeta`;
   RENAME table `wp_posts` TO `wp_yoursitename_posts`;
   RENAME table `wp_termmeta` TO `wp_yoursitename_termmeta`;
   RENAME table `wp_terms` TO `wp_yoursitename_terms`;
   RENAME table `wp_term_relationships` TO `wp_yoursitename_term_relationships`;
   RENAME table `wp_term_taxonomy` TO `wp_yoursitename_term_taxonomy`;
   RENAME table `wp_usermeta` TO `wp_yoursitename_usermeta`;
   RENAME table `wp_users` TO `wp_yoursitename_users`;

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2. Prabhudatta Sahoo

   When I am renaming my tables in the database all the images in the gallery are going away, I do not understand the reason. Could anyone please help me fixing this issue?

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   • Terry Thorson

     This issue will occur if you do not update the serialized data strings (used for your gallery images) correctly in the database. A good way to do this is to use the plugin WP Migrate DB. There is an excellent tutorial for this on Lynda.com (although be sure to use the same prefix for your target database as your source database).
     I learned this the hard way. Trying to start afresh, I discovered my backup was faulty as well. Luckily my webhost had an older backup I could use to restart my migration. WP Migrate DB did the trick.

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3. Cameron Jones

   I can’t find any fields in the _usermeta or _options tables that would require updating. Unless they are specifically referencing a table, they shouldn’t need to be updated. It’s a table prefix, not a variable prefix.

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   • Cameron Jones

     Actually, I stand corrected. There are a couple that will be part of a default WordPress install:

     In prefix_options
     prefix_user_roles

     In prefix_usermeta
     prefix_capabilities
     prefix_user_level
     prefix_dashboard_quick_press_last_post_id
     prefix_user-settings
     prefix_user-settings-time

     You should be careful regarding updating any other fields. Plugins may either use the defined prefix or `wp_` as a prefix. Always make a backup and test on a dev or staging environment.

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4. kapil

   hi,
   i have a query. assume that i have changed all my prefix from wp_something to some other name. these changes will be done to the existing fields in the database only. but wont the codes in my wordpress .php files remain the same??? so next time for any new user registration or some other registration, the entities will again be saved as wp_something as the main code in the .php files remains unchanged… ???

   thanks….

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5. tech

   UPDATE `wp_a123456_options` SET `option_name`=REPLACE(`option_name`,’wp_’,’wp_a123456_’) WHERE `option_name` LIKE ‘%wp_%’;

   UPDATE `wp_a123456_usermeta` SET `meta_key`=REPLACE(`meta_key`,’wp_’,’wp_a123456_’) WHERE `meta_key` LIKE ‘%wp_%’;

   I do changes but after doing this i again run following query it shows prefix not changed
   SELECT * FROM `wp_a123456_options` WHERE `option_name` LIKE ‘%wp_%’

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   • Wiem

     Thank you for the queries

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6. Nathan WHite

   This post and the responses to the comments leaves out a very important component. Does the table need to begin with wp_ ?

   Coming upon another discussion in wordpress.org indicated that it indeed did not need to. It would have helped me if this question was answered by the moderator.

   Also, dismissed_wp_pointers questions were not clearly answered. I changed mine.

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7. Clare Wood

   Hi guys,

   I followed these steps, now when I try to see the back-end or front-end of my site I get this:

   ERROR: $table_prefix in wp-config.php can only contain numbers, letters, and underscores.

   I’m positive I only have lowercase letters and an underscore as my table prefix.

   Any ideas? The site is on localhost.

   Cheers.

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8. Paul

   Fantastic and logically prepared article on Wp security.

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9. Thomas

   Thanx a bunch! I tried to restore my old database, but to no avail. Then I figured out that my new database prefix was different from old. Made all that you recommended and vuala!

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10. Divyesh

    Thanks a Lot!!!
    It worked like a charm

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11. Nikhil

    I am getting this error…….”You do not have sufficient permissions to access this page” after implementing above procedure…..how to solve it?????

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12. Saz

    These instructions have been followed but now role assignment for new users has disappeared…

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13. Tom

    Thanks for a great tips .
    I have a question.
    Do I need to change “wp_ ….” used in post_meta table as well?

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14. johnny

    or this plugin http://wordpress.org/plugins/db-prefix-change/

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15. savagemike

    For the wp_options and wp_usermeta tables, why not dump the database and use sed to replace “wp_” with the new prefix? Example:

    sed -i ‘s/wp_/wp_1234/g’ > filename.sql

    Then, simply import the modified dump. Easier and faster than changing cells one-by-one.

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16. gcreator

    Attacker can simple use ‘%wp_%’
    I mean that is not fully secure at all…
    because he knows the table names that wordpress generates he can simply use ‘_%users’ for wp_anything_users OR ‘_%posts’ for ‘wp_anything_posts’ ..etc…

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    • Jim

      gcreator…

      For 99% of the attacks against WP databases, the skiddies are using pre-built tools and default settings. This gets you out of their crosshairs.

      if you are under focused attack then yeah, simple obfuscation will only slow them down, not completely protect you.

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17. javed

    thanks a lot

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18. gabe

    I got syntax error when following this (my version of SQL is 5.5.x).

    I had success after referring to the SQL manual. Needed to leave the quotes out of the query:

    [WRONG] RENAME table ‘wp_links’ TO ‘wp_xx_links’;
    [RIGHT] RENAME TABLE wp_links TO wp_xx_links;

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    • RosellaBird

      Thanks! That saved me a lot of time I had the same error too

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    • Sepster

      You were using “standard” quotes ‘. The correct syntax to identify object names in mySql is to use “backquotes” ` (ie the key in the top left of a standard-US keyboard, left of the number 1)

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    • Marcello Nuccio

      The problem is that you are using the wrong quotes. You must use the backtick character around table names, not the apostrophe. In SQL, the apostrophe is used to delimit strings.

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19. Karen

    I have changed the prefixes of a new install and then built a whole new site! I suddenly realised that I might not be able to update wordpress as normal from the admin panel..

    Does changing the prefixes affect being able to update wordpress as normal???

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20. Pablo

    Nice.

    You can use this as well:
    UPDATE `wp_a123456_options` SET `option_name`=REPLACE(`option_name`,’wp_’,’wp_a123456_’) WHERE `option_name` LIKE ‘%wp_%’;

    UPDATE `wp_a123456_usermeta` SET `meta_key`=REPLACE(`meta_key`,’wp_’,’wp_a123456_’) WHERE `meta_key` LIKE ‘%wp_%’;

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21. Haary

    Please answer ” How to create a plugin for take a backup of speific table in wordpress database?” in the stackoverflow

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22. Haary

    It is a nice tutorial. Please see the link http://stackoverflow.com/questions/21546786/how-to-create-a-plugin-for-take-a-backup-of-speific-table-in-wordpress-database

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23. David Appleby

    Very nice guide thanks.

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24. Andrew Rickards

    Thanks for the useful info. I just tried changing my DB prefix and everything seems to have worked perfectly.

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25. John

    Thank you for doing the work to inform us on this topic. I have zero experience with WordPress, mySQL and PHP, so your help is greatly appreciated. A couple of questions:

    You have a graphic right below the words “There are a total of 11…”, with SQL circled. Am I supposed to check all the checkboxes?

    In the section titled “The Options Table”, which I’m getting to next, you say “This will return a lot of results, and you need to go one by one to change these lines.” How is this done (or will it be perfectly obvious)?

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    • WPBeginner Support

      John, you need to click on the SQL which will open a Text Area, copy and paste the query given below the circled screenshot into SQL textarea and click Go button.

      When updating options table you will run another SQL query to search for fields which have wp_ in them and replace those fields with your new database prefix. The query will return a number of rows you need to click on the Edit button next to each row to edit it and manually replace wp_ with your new database prefix.

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      管理者

26. Iftekhar

    Dear writer, I have tested this in my local server. I am having problem to get access in my admin panel after changing table prefix. I have found “dismissed_wp_pointers” this in my database. Do I need to change it also?

    Thanks in advance

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    • WPBeginner Support

      No we don’t think you need to change that.

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      管理者

      • Iftekhar

        Problem solved :). Actually I forgot to change option table. Thanks for reply.

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      • AMSGATOR

        `dismissed_wp_pointers` shows up when querying SELECT * FROM `wp_a123456_usermeta` WHERE `meta_key` LIKE ‘%wp_%’

        So I changed it since this says to change all the wp_ to the new prefix. I hope it doesn’t break anything.

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27. Kobbe

    Is this tutorial for an already installed blog…? Please kindly brief me on how to do this on a FRESH installations.

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    • AMSGATOR

      If you have already installed WordPress (regardless of how much you published) and you want to change the prefix then follow this tutorial.

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28. blurped

    Great guide, works like a charm. One question- why did you leave ‘wp_’ in the new prefix? Seems like a whole lot of effort to change your table prefixes but still leave that fragment in there. Just remove it completely or replace it with something else more random (like ‘eh_’ or whatever)

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29. yerom

    Well, everything is just fine… But when i’m go back to my site, it makes me the 5 minutes install again…
    I think i missed something.

    Anyone had the same issue ?
    Tks !

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    • WPBeginner Support

      Check your wp-config.php file, it seems like you forgot to update $table_prefix value.

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      管理者

30. ideal ismail

    hi Admin,

    Regarding the naming convention for the table prefix, “Note: You can only change it to numbers, letters, and underscores. Feel free to mix uppercase and lowercase.”

    this is not true. You CAN’T use uppercase as it will wreak havoc with your database entries. i personally encountered this and the solution is to restrict to using numbers, underscores and lowercase letters.

    many other people have encountered this. a quick google search gave me the following:
    http://wordpress.org/support/topic/case-sensitive-wp_table_prefix?replies=1
    http://stackoverflow.com/questions/9827164/wordpress-keeps-redirecting-to-install-php-after-migration
    http://esdev.net/wordpress-error-you-do-not-have-sufficient-permissions-to-access-this-page/#.Ui_pHtJkMwB

    hope that helps.

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    • Editorial Staff

      Updated the article.

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      管理者

31. Steve

    Couldn’t you just back everything up,
    export the DB to a DBbackup.sql file
    open it with a text editor.
    do a global search and replace and replace wp_ with mynewprefix_
    Save the file,
    drop all the tables in the DB
    and import the new DBbackup.sql?

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    • Editorial Staff

      You could do that

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      管理者

      • Steve

        Update – The global search and replace works. However, it might work too good. One of the side effects is that it returns all of your widgets to the default (fresh install) state.

        Luckily – it returns them to the “inactive section” so you don’t have to completely re-do them. My lesson learned was to take a screen shot of the dashboard (before) so it’s easier to remember where you had them all.

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32. Ahsan

    Hey after changing table prefix and table name from mysql when i refresh the website it says website has a redirect loop, what should i do?

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    • Andrew

      leave the database changes to the professionals…………..

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    • GReg

      Update the prefix definition in config.php

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33. Katie

    Tried to do this on a multisite database install… totally failed. I seemed to put all the queries in correctly, but I got errors and at the end of all the steps my site was just redirecting itself indefinitely…

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34. Mike

    I did these changes as instructed but now I can’t get to my admin page.

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35. Mark Pescatrice

    Well after about 30 minutes of sweating bullets, I was able to do this. I made one tiny typo on wp-config.php. but otherwise it went smoothly. I did use Duplicator to create a backup before starting all of this.

    I recommend users to do the following additional steps:

    Before starting, put a dummy index.html in the root folder of your WP install, and renaming index.php to index.php.tmp (or something similar). After making a tiny typo in the wp-config.php file, I found myself at the WP install page.

    After you are done, rename index.php.tmp to index.php and remove or rename the index.html page.

    Thanks for the great article. I’m curious to see how the changes will affect the spam count.

    Mark Pescatrice

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36. Al Lemieux

    In terms of process, do I make these security changes locally first? Or do I make them on Wordpress?

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    • Editorial Staff

      You make them on WordPress.

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      管理者

      • Dana Nourie

        After changing the table prefixes, I can log in and all the content is there, but I’m not getting the admin interface. Any idea what I should check?

        Thank you!
        Dana

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        • Dana Nourie

          Nevermind, I had to change entries in the options table.

37. Corey

    What about things like this? Do we need to change the wp in this, or only when it starts with wp?

    dismissed_wp_pointers

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    • Editorial Staff

      You should be able to change it to whatever you like.

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      管理者

      • ana

        I am confussed about ‘ _site_transient_timeout_wporg_theme_feature_list ‘ these, do I have to change wp here as well? and if yes then plz give an example.

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        • AMSGATOR

          You should only have to change it if wp is followed by an underscore (i.e., wp_)

38. Eric

    Awesome information security for wp anti thief..But is there any free plugin or software to automate these processes?

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    • Editorial Staff

      Don’t think there is.

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      管理者

      • Yann

        Thanks for the tutorial.
        Here a plugin to automate these processes : http://wordpress.org/extend/plugins/wp-security-scan/

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    • Daniel Garneau

      All In One WP Security plugin has a Database Security option for editing the prefix of an existing WordPress database. I have been using the plugin for several months now, but I have not used this feature yet.

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39. Orion

    just tried this out, everything changed according to your instructions, hopefully this keeps the russians out….for a while at least.. Thank you for posting.

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40. Benno

    Thanks, worked great on my new blog!

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41. Debra

    I must be a total idiot because I sure can sort this out. Can’t even find the wp database. Geez this is frustrating

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    • Editorial Staff

      Which web hosting service are you using?

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      管理者

42. Scott Semple

    Successfully changed the database prefixes, but now I can’t sign in?

    My ##_capabilities in ##_usermeta is for an admin: a:1:{s:13:”administrator”;s:1:”1″;}

    Thoughts on why I still can’t sign in? Thanks!

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    • Editorial Staff

      It loads the website properly, but you can’t sign in? What error does it say… Incorrect password? or incorrect username?

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      管理者

43. mckenzie

    thanks so much! i searched all over the internet and you are the only blog entry to get this right on the spot!!

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44. rawalbaig

    Please Help me I’m not able to process the last two steps For “The Option Table” I’m Here http://imageshack.us/photo/my-images/819/img00.png

    & ‘”UserMeta Table” Here http://imageshack.us/photo/my-images/84/img002o.png

    What to do next I’m not able to login my wordpress account

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45. TrentJessee

    Excellent security post, and well written. What would you charge to do this service for people? Thanks!

    http://trentjessee.com

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46. WesHopper

    @wpbeginner @WesHopper

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47. wpbeginner

    @WesHopper You just manually change it. Because the number vary based on the plugins you have.

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48. Keith Davis

    Hi Admin
    Good clear instructions but I’ve never had the confidence to attempt a database prefix change – just in case!

    You boys provide some great stuff – much appreciated.

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49. Leonco

    Very interesting security steps…

    But surely there has to be a security plugin that addresses
    the issue of preventing hacking.

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    • João

      There are several plugins that do this, but the truth is that it’s always good to know how to do this yourself.

      For example I had an (apparently) buggy plugin change my WordPress database prefix just now, and i was locked out of my own WP installation.

      This simple guide showed me how to undo the damage.

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50. Vivek Parmar

    Thanks a lot for sharing this. it is essential to secure WordPress first before posting any content your blog.

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