I wanted to pull the database from my production wordpress website into an offline development copy of it on my desktop machine so I could modify the site and test it with a
full set of the existing blog content and history.
This proved to be problematic, as simply making an offline backup of the database and importing it into the local development database did not work.
Overcoming these problems in moving data from the production to the dev database can probably be used to go the other way as well - so I think you can just use these guidelines for what you want to do as well - just start with dev data and move it to prod.
The problems here were:
- the permalink designations for the
blog posts are all stored in the
database as they would be for the
online version, but my offline copy
isn't at the domain address, instead
it is in the localhost directory. So
when I launch the site locally,
although the css formatting and
images are all in place (the image
links being relative), the actual
blog posts don't show up.
- many of the links throughout the
site link back out to the internet,
so if you try to navigate to
archives, or comments, or
categories, or the main posts, you
get sent back out to the internet
instead of staying in the database
on the local machine.
To make sure I was doing this right, I blew away the wordpress install I had on my local machine and restarted from scratch.
Once I had a clean, new wordpress install and brand new default freshly created local database for it, I opened up the database in phpMyAdmin and took a look at the wp_posts
table. Inside there, each record (in other words, each post) has a column titled "guid", which shows the location of that post. For example, the first one in a fresh, default
install contains this "guid" value:
http://localhost/wordpress/?p=1
If you look in the wp_posts table of your online version, you'll see instead in this location the url to your site online.
You can't just import the tables wholesale into your local install, because you'll be importing all these outside references. It will make your local version impossible to navigate locally.
So, I created a backup copy of my online site's database and saved it locally as a .sql file. I then opened that file in a text editor (I used notepad++, a great piece of free software, but you could use any text editor). Things I needed to look out for:
- For whatever reason, the tables on my
online site aren't just, for example,
"wp_posts" - they are
"wp_something_posts"... there are
some extra letters in there in the
table names.
- Any references to http://... that contain my online url instead of localhost/wordpress
To keep it simple let's just do only the posts. In the backup copy of the .sql you've made of your online database, find the beginning of the wp_posts table. It will look something like this:
--
-- Table structure for table `wp_posts`
--
DROP TABLE IF EXISTS `wp_posts`;
CREATE TABLE `wp_posts` (
...and so on. Highlight everything above that up to just below the comment marking the beginning of the database at the top of the file (it will say -- Database: 'your database name') and delete it. Then go to the end of your wp_posts table, and delete everything after then end of it down to the bottom of the file. Now your file only contains your posts, and nothing else.
Save this as a separate document. Call it posts.sql or something like that.
Now, in this posts.sql file, you need to do two find/replaces actions.
- Find every instance of the name of
the table wp_something_posts and
replace it with wp_posts. You only
need to do this if your backup copy
of your online database doesn't
match your clean local install as
far as the table names go. You want
whatever the table name is in this
file to match what your locally
installed wordpress database has as
this table name. If you don't make
these names match, you are just
going to end up importing the posts
into a new, differently named table,
which will be of no use to you at
all.
- Find every instance of http://...
(replace the elipsis with your url)
and replace it with
http://localhost/wordpress (or
whatever the local url to your dev
version of the site is)
Now save this file again, to make sure you've got these changes set.
Now that you've done that, use phpMyAdmin to get into the wordpress database on your local machine, select the "import" tab and navigate the selector to the posts.sql file you just made, and then import it. This will pull all the data in that file into your local wp_posts table.
When that finishes, browse your local wordpress site. You'll see all your posts in there now. Hooray!
You may need to do something similar for a few other tables if you want to bring in your comments, tags, categories, and static pages you've created, etc.
I realize this is a convoluted process. There is probably a tool out there somewhere that makes this activity easier, and if someone knows of one I'd love to find out about it. If someone knows of a better way to do this manually than what I've described, I'd love to know that as well!
Until then, this is the way I figured out how to do it. Hopefully it helps get you going in the right direction.