SQL Refresher Course
Refresh your SQL skills with hands-on queries, joins, indexing, and schema design for real client–project–ticket data. Learn to write faster reports, improve data quality, and optimize performance for modern tech and data engineering roles.

flexible workload from 4 to 360h
valid certificate in your country
What will I learn?
The SQL Refresher Course quickly sharpens your skills with practical queries for reporting and analysis using real client, project, and ticket patterns. You will review joins, aggregations, filters, window functions, and date handling, then move into schema design, constraints, indexes, and execution plans. Learn safe updates, test data techniques, and clear DDL so you can write faster, more reliable queries in any modern SQL dialect.
Elevify advantages
Develop skills
- Write clean SQL joins and filters for fast client, project, and ticket reports.
- Design solid schemas with keys, constraints, and enums for tech-grade data models.
- Tune indexes and read query plans to quickly speed up slow production queries.
- Use transactions, constraints, and checks to keep operational data accurate.
- Create and seed tables with safe INSERT patterns and realistic test data fast.
Suggested summary
Before starting, you can change the chapters and workload. Choose which chapter to start with. Add or remove chapters. Increase or decrease the course workload.What our students say
Your classes are perfect. I purchased the one-year package and finally have the chance to follow several topics I'm interested in without needing to switch platforms... I appreciate everything you do, I've already recommended you to others...

Giulio CarloDigital Marketing Student
I like how the lessons are straight to the point and how I can switch chapters and skip content I don't need.

Mariana FerresPhotography Student
I like the content and the way the videos are presented and transcribed, which speeds up the process!

Luciana AlvarengaNail Design Student
The platform is fast and easy to use. The variety of content and the supplementary videos really help with learning.

Giulio CarloPrompt Engineering Student
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