Instructor since 2023
Aiko Tanaka
Analytics lead teaching SQL that answers business questions, from first SELECT to window functions
Sample
- Students
- 6,830
- Courses
- 3
- Instructor rating
- 4.4
- Reviews
- 23
About Aiko
I have spent most of my career turning vague questions into queries: which customers came back, where the funnel leaks, why revenue looks different in two reports. SQL is the tool I reach for first, and I teach it the way analysts actually use it.
My courses use realistic datasets with messy edges: duplicates, missing values, time zones and late data. You will learn to check your own results, explain a query to a colleague and keep cloud warehouse costs under control.
I write every exercise so it runs on free tools, PostgreSQL, DuckDB or the BigQuery sandbox, so you never need a company account to practise.
Courses by Aiko
What students say
Grace O.
Sample Guardrails should be standard
We now set maximum bytes billed on all analyst accounts. Simple advice that every team should follow.
Arjun K.
Sample Window functions without fear
Ranking and LAG explained with small examples before the real queries. I am no longer scared of OVER.
Julia N.
Sample Cut our BigQuery bill noticeably
The INFORMATION_SCHEMA lesson found a dashboard scanning a big table every few minutes. Fixing it paid for this course many times.
Andrei V.
Sample Gaps and islands finally clicked
The hand worked table for the row number difference trick made it obvious. I used it for login streaks the same week.
Tom B.
Sample The NULL lesson saved a report
I had a filter silently dropping rows with NULL. After lesson two I found it in a report my manager uses weekly.
Mohammed A.
Sample GA4 section is excellent
Extracting event parameters always confused me. The scalar subquery pattern made it clean and readable.
Mariana C.
Sample Sessionization lesson is gold
We replaced a slow Python job with the SQL sessionization pattern from this course. It is faster and easier to review.
Anika R.
Sample UNNEST finally makes sense
The example where order counts doubled after unnesting is exactly the mistake I made last month.