Here are some directions for backing up and restoring your wordpress db.
https://codex.wordpress.org/Backing_Up_Your_Database
I used it to convert my beta site to RC1. Pretty straight forward.
is the site you want move WPMU ?
If yes, do you want install bp or move to a new site ( new domain name i mean ) ?
If moving to a new domain, backup your DB & restore it to the new server, after that, go to wp_sites, wp_1_option and replace the old site domain with the new one
Thanks for your responses folks. Allow me to explain my query a bit in more depth –
Existing Site:
Exists since last 4-5 years; created by an amature web designer using php-mysql. The fella is refusing to cooperate and all I have is access to .sql dumps of individual tables of the existing database.
The current website only provides simple functionality to accept data from users through a form [typical form consisting of First Name, Last Name, Year of Graduation, Branch, Phone Number, Email ID, Current Employer, Profession etc.).
What I have done so far:
Created a WPMU powered site on my computer using XAMPP installation. Before I take it to the Internet, I’ll have to present a demo to my college. For that, I need to import the data of existing users from existing database to WPMU database.
To keep the things simple, I have replicated the input fields of existing website into my WPMU site.
Problem:
I want to have all the old information imported to my new WPMU database so that the old users do not have to re-register on the new website.
What I’m thinking:
If I can import the .sql dumps from existing database tables (I have individual table backups!) to WPMU tables.
What do you think? Is there a better way to solve the problem? Please suggest.
PS: I love WPMU & Buddypress. Awesome creation, guys! 
Hi,
We had same problem when we moved our installation to WordPress MU + BuddyPress
So, I have developed a plugin for importing members to WordPress MU + BuddyPress installation.
It might be useful for you as well, please check it in https://buddypress.org/extend/plugins/
@Manoj: I think your plugin imports existing wordpress users. In my case, the existing database is not wordpress.
One more question; how do I import their passwords without exposing them?
No, It will import all data from the given box in [|] delimit format. So you can format your data as per given example and import.
Also currently it doesn’t have any functionality to import the password.
Are you using any data encryption for password?
Hello Manoj!
Thank you for your response. I installed your plugin and it worked (there was an error on activation; but it let me do the job).
I delved more into the non-wpmu database I have (created few years ago) that stores passwords as simple text! So I can view everyone’s password. This is troublesome!
My challenges are as follows –
1. Import the old data & other fields to corresponding WPMU database fields
2. Convert their passwords to encrypted passwords.
3. Send activation mail to all the users [handled by your plugin]
How can I go about 1 & 2 above?
Are you using BuddyPress or Just WPMU?
Please let me know the error while activating the plugin.
I’m using Buddypress [of course which works through WPMU]. I could not replicate the error. But I’ll try uninstalling and installingthe plugin. I did it on XAMPP.
Hey Manoj Kumar
great plugin… couple of questions
no matter how I format the user data, I always get “1 Error” and “processing complete”
example
username|firstname lastname|email@email.com => 1 Error
also, I’ve changed the “Full Name” profile field to be “first name” and added an additional field for “last name”… how does that change the format?
like this now?
username|firstname|lstname|email@email.com ?
thanks for your help
My challenges are as follows –
1. Import the old data & other fields to corresponding WPMU database fields
2. Convert their passwords to encrypted passwords.
3. Send activation mail to all the users [handled by your plugin]
how many users do you have?
can you not simply enter them by hand and let WPMU generate a “new/temporary” password
yourcurrentuser|theirfirstname theirlastname|theiremail@email.com
that would
– Hash/encrypt their password (they still have to login and change it)
– import them into the DB
– send activation email/username + password
just a thought
Well that would be bit difficult but not impossible because we have about 2200 users to be imported from old database. I also need to import their other profile data. Is this possible?
I will work towards enhancing this plugin whenever I get time.
Please put your wishlist regarding bulk import users at plugin page.
@ Manoj
thanks for answering me on your site… I\’ll move my issues to this thread
while the \”Full Name\” field cannot be changed, I was able to change it by duplicating the url to change a different field…
example:
when you edit any of the xprofile fields, the url shows somwthing like this:
http://mysite.com/wp-admin/?edit=profile_pageID=2
i just changed the \”2\” to a \”1\” and hit refresh…that allowed me to change the \”Full Name\” field to \”first name\”
my install is very customized, so I simpley can\’t \”roll back\” to a fresh install…
I will try changing the profile name back to \”Full Name\” and see if that works….
(more to follow)
@ theBigK
Well that would be bit difficult but not impossible because we have about 2200 users to be imported from old database. I also need to import their other profile data. Is this possible?
it doesnt look like you can add any additional information currently, however this plugin isn\’t super-complex, so you could probably add the functionality to add more user data by adjusting the PHP code (not sure how though)
you may also be able to export your SQL file in a | \”pipe\” delimited fashion
something like this:
\’
SELECT * FROM TABLE
ORDER BY ID INTO OUTFILE \’out.file\’
FIELDS TERMINATED BY \’|\’;
\’
I dont know much about this, but google it and Im sure you\’ll find something
Thanks. I’m not good with php/mysql 
.
Novice here… this should be fun. (July 2014)
I got someone to import users in to my sweetdate (2.6.1)/buddypress (2.5.4) site. The users are there in the WordPress users, but not in the Buddypress site. They don’t even show up in the Pending Activation. I can see them in the SQL Database.
How can I migrate them in to the Buddypress members, searchable, database.
Thanks in advance.
