How to Connect MySQL to Looker

Why connect MySQL to Looker?

Looker needs a live database connection to generate SQL, build Explores, and surface dashboards. Connecting MySQL lets teams analyze transactional data—orders, customers, products—without ETL.

What prerequisites do I need?

Ensure the MySQL instance is reachable from Looker’s IPs, grant a read-only user, and enable SSL if required by your security policy.

How do I create a MySQL connection in Looker?

Step-by-step UI walkthrough

1. Admin → Connections → New Connection
2. Choose “MySQL”.
3. Fill host, port, database, username, password.
4.Toggle SSL if used.
5. Click “Test” then “Add Connection”.

Required JDBC parameters

Add useCursorFetch=true for large result sets and zeroDateTimeBehavior=convertToNull if your schema has 0000-00-00 dates.

How to verify the connection works?

Open SQL Runner, pick your new connection, run SHOW TABLES. Seeing Customers, Orders, Products, and OrderItems confirms access.

How to model ecommerce data after connecting?

Sample Explore from Orders and Customers

Create a view for each table, then use explore: orders and join: customers with sql_on: ${orders.customer_id} = ${customers.id}.Users can now slice revenue by customer attributes.

Best practices for performance

Index foreign keys (Orders.customer_id, OrderItems.order_id), upgrade to MySQL 8+, and limit Explores with persistent_derived_tables to pre-aggregate.

Common mistakes & fixes

Incorrect timezone: Set default_timezone: "UTC" to prevent shifted timestamps.
Missing privileges: Grant SELECT on all schemas you intend to model; Looker fails silently if tables aren’t visible.

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