> ## Documentation Index > Fetch the complete documentation index at: https://docs.xano.com/llms.txt > Use this file to discover all available pages before exploring further. # External Database Query In Xano, you can connect to the following types of external databases: * PostgreSQL * MS SQL * Oracle * MySQL * Snowflake Add a new function to your function stack that corresponds to the type of database you'd like to connect to. The external connection functions are located under Database Operations.

Once you've added your desired connection function, you'll need to define a **connection string**. A connection string is just a URL that contains all of the information we need to connect to your database, such as a hostname or IP address, port, username, and password. We've added an easy to use panel to help you generate a connection string for your database.

Fill in the required information and click **Save** at the bottom to generate your connection string. ### Dynamic Connection Strings Connection strings don't have to be static. You can reference **variables** or **inputs** as your connection string, and apply **filters** to dynamically construct them at runtime. This is useful when you need to connect to different databases based on context — for example, routing to a specific tenant's database or switching between environments. For more information on building a query to run against your database, see our [Direct Database Query documentation](/the-function-stack/functions/database-requests/direct-database-query).