Best thing to do is read the docs: http://codex.wordpress.org/Tools_Export_Screen and http://codex.wordpress.org/Importing_Content#WordPress and work with WXR files rather than trying to export directly from the database.
You also have the option on Import to grab images. Or you can merge the contents of the three wp-content/uploads/ directories, but be aware that it’s possible some images may have the same name and get overwritten.
Related Posts:
- How can I trust switch_to_blog()?
- DB connection error after copying a WordPress Multisite instance to a second location
- Add WordPress MU Network Admin via Database
- How to tell which database tables belongs to which multisite site
- what are pmxi tables? [closed]
- Shared table across network
- find a random blogid across my multisite network that has at least one post published
- WP-CLI methods for get_current_blog_id, get_blog_details or $wpdb->prefix
- Multisite: How to store global options vs. site options?
- Uploading/Deploying a Multi Site Install
- Multisite database upgrade SSL error
- Configure WordPress to read from database only, never write
- Multiple Domains and Subdomains Using Multisite Installation
- Is it possible to fix/repair all Index, Primary Key, Unique (and all other) structure of a WordPress MS Database
- Migrating WPMS from apache to IIS7 causes Database Error
- Synchronizing Two WordPress Sites Content
- How to clone and locally run a network for testing
- Two WordPress sites sharing the same database
- Fixing media links after importing to multisite
- Is it possible to import a wordpress backup from a single site in to a multi-site configuration?
- Split a database will improve performance?
- How to Move Local Singlesite Database to Remote Multsite Database?
- Multisite Subdomain Using More Resources Than Others?
- How to change the database prefix in multisite (WPMU) install
- Make WordPress Search for Both Main Domain and Subdomain
- Does WordPress MultiSite use separate MySql databases?
- Bootstrapping WordPress MultiSite Outsite of WordPress – No $wpdb
- Multisite setup creating custom table
- Is there a way to run upgrade.php for one blog?
- Within the database, where is the flag which says that a user has Super Admin rights?
- Bulk activate a theme on multisite
- Migrating Multisite – Database error, missing wp_blogs table
- How to store custom user data on the database?
- WPML tables not deleted when removing multisite subsite, need help clearing up my sql-file! [closed]
- Database Tables Lost Indexes? How to Recover?
- Installed domain-based Multisite but can’t access wp-admin (redirect loop)
- Multiple multisite instances connecting to the same database
- WordPress Multisite – can I somehow merge the tables?
- Multisite with subfolders- can’t access main site- Error establishing a database connection
- Create a database for each site created in multisite?
- Use WordPress MultiSite (WPMS) with a remote database for each created site
- Will changing the folder name two directories above a fresh wordpress installation break the site?
- WordPress Multisite blogs not working after domain swap
- Least expensive way to get table prefix in multisite installation
- 2 website 1 database… Local to online
- new multisite, old db
- Removing Mutlisite lines stop DB connection
- how to migrate wpmu from one host to the other?
- Share DB tables between two blogs on the same WP Multisite installation
- How can I create blog specific database table in multisite?
- How many databases do I need?
- Locking one blog of many in a multi user/blog WordPress installation
- WordPress Multisites or Multiple WP Single sites?
- $wpdb->update prefixes database name to table when executing query
- WP MultiSite: Can’t select database error after changing to new domain
- Combining user database tables while keeping all other data in seperate for multiple sites?
- How to make multi site with single Database?
- Update WP install to WP network & it broke the DB connection
- Sharing users across multiple sites, each on their own database
- importing data into wordpress db
- How to share User Database between Two Multisite Installations + More
- How long is “as long as possible” in wp_cache_set()?
- WPMU on MySQL limited to 1GB of space?
- Questions about MU database schema and how to list all blogs
- How does WP decide how to evaluate database integrity
- How to use the same users table on multiple wordpress sites
- A database for each category?
- how to convert a wp multisite into a single site with content from subsites
- Problems with WordPress multisite directories/url structures and admin access after migration
- allow multisite in the installation process
- Error establishing a database connection after moving local wordpressmultisite from one directory to another
- Will resetting my database affect other sites on my multisite WordPress install?
- WordPress Database Cleanup
- Optimal setup for Multi Domain WordPress with Woocommerce
- wordpress multisite – handle Database
- Importing Posts into New Website with Same User ID’s
- WordPress automatic Login on other page?
- How to reconnect database to existing wordpress multisite setup after changing site name
- Multi-site database upgrade claims success, but db_version not updated
- Get multisite count without php?
- How to create 30 new sites from an export of a master site?
- Multiple domain with one database
- Problem in adding new site on WP multisite
- WordPress and SQL – Update and Insert from another table if column value doesn’t exist
- MySql Database In WordPress Multisite
- WP DB Location for “Next Post to Create” Index Value
- Error establishing a database connection – Multi-site with subsite don’t exisit [duplicate]
- Plugin data shared in Multisite
- Merging versions of wp_posts based on post_title
- WordPress multisite and one database
- WordPress Multisite platform for different city for single db
- 4th Network Site Database Errors?
- Is there a full explanation on how to share a database with two WordPress sites on same server?
- HyperDB, Multisite – on new site creation put site’s tables to specific database
- subdomain archiving
- No My Sites link after installing Multisite
- Error uploading files bigger than 58 MB
- Link structure, WordPress IIS
- Multisite with Different URLs on Local Server
- After cloning my WordPress database to another server, I cannot log in