How to design a multi tenant mysql database

Question

Let us say I need to design a database which will host data for multiple companies. Now for security and admin purposes I need to make sure that the data for different companies is properly isolated but I also do not want to start 10 mysql processes for hosting the data for 10 companies on 10 different servers. What are the best ways to do this with the mysql database.

Answer 1

There are several approaches to multi-tenant databases. For discussion, they're usually broken into three categories.

• One database per tenant.
• Shared database, one schema per tenant.
• Shared database, shared schema. A tenant identifier (tenant key) associates every row with the right tenant.

MSDN has a good article on the pros and cons of each design, and examples of implementations.

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Microsoft has apparently taken down the pages I referred to, but they are on on archive.org. Links have been changed to point there.

For reference, this is the original link for the second article

Answer 2

In MySQL I prefer to use a single database for all tenants. I restrict access to the data by using a separate database user for each tenant that only has access to views that only show rows that belong to that tenant.

This can be done by:

1. Add a tenant_id column to every table
2. Use a trigger to populate the tenant_id with the current database username on insert
3. Create a view for each table where tenant_id = current_database_username
4. Only use the views in your application
5. Connect to the database using the tenant specific username

I've fully documented this in a blog post: https://opensource.io/it/mysql-multi-tenant/