SQL Intermediate
Move beyond beginner SQL with advanced query patterns and SQL-based data cleaning.
Intermediate · 3 course parts · 3 capstone projects · Certificate included.
SQL Intermediate Course Learning Features
Build Multi-Step Queries
Use subqueries, derived tables and CTEs to break complex analytical questions into readable steps.
Built-In AI-Assisted Editor
Practise intermediate SQL directly in the learning environment without separate setup.
AI Tutor, On Demand
Get task-specific guidance on syntax, logic and debugging while you work through each problem.
3 Capstone Projects
Complete one applied project after each part: retrieval patterns, advanced filtering, and data cleaning.
Build Practical Intermediate SQL Skills for Analytics
SQL Intermediate is designed for learners who already understand core SQL and are ready to solve more layered analytical problems. Three parts focus on advanced retrieval patterns, advanced filtering and conditional logic, and preparing messy data for analysis directly in SQL.
Skills you'll gain
- Use subqueries in SELECT, WHERE, and FROM
- Write correlated and nested subqueries
- Use derived tables and CTEs to structure multi-step logic
- Apply EXISTS, NOT EXISTS, ANY, ALL, and advanced CASE expressions
- Use COALESCE, IFNULL, and NULL-safe filtering correctly
- Clean strings, convert data types, work with dates, and detect duplicates in SQL
Hands-on learning
- Write and run every query in the built-in AI-assisted editor
- Practise with familiar education-related tables used across the SQL foundations sequence
- Work through realistic analytics questions rather than isolated syntax drills
- Use the built-in AI tutor for task-specific hints and explanations
- Complete three capstone projects — one after each course part
Who should take this course
- Learners who have completed SQL Intermediate or equivalent foundational SQL study
- People preparing for data analyst, BI, reporting, operations, and data-focused roles
- Learners ready to move beyond simple SELECT, WHERE, JOIN, and GROUP BY queries
- Professionals who want cleaner, more structured SQL for real-world analysis
Prerequisites
- Comfort with SELECT, WHERE, JOIN, GROUP BY, and basic aggregation
- SQL Intermediate is the recommended preceding course
- No prior AI tool experience is required
SQL Intermediate Curriculum: 3 Applied Parts
Three parts move from layered retrieval to more advanced filtering logic and finally to SQL-based data cleaning — the core patterns used when beginner queries are no longer enough.
Learn how to structure multi-step questions by placing one query inside another or naming intermediate results before the final query.
- Subqueries in SELECT, WHERE, and FROM
- Correlated subqueries
- Derived tables
- CTEs (Common Table Expressions)
- Nested subqueries
- Subquery vs. CTE vs. derived table — when to use each
- Capstone 1: Multi-Step Enrollment Report
Use more expressive conditional logic to test relationships, classify records, compare against sets, and work safely with incomplete data.
- EXISTS and NOT EXISTS
- ANY and ALL
- Advanced CASE patterns
- COALESCE and IFNULL
- CASE with aggregations
- NULL-safe filtering with IS NULL / IS NOT NULL
- Capstone 2: At-Risk Student Audit
Prepare raw data for analysis directly in SQL by standardizing text, converting types, handling dates and NULLs, and identifying duplicate records.
- TRIM, UPPER, and LOWER
- CAST and CONVERT
- Handling messy strings
- Date functions such as DATEADD, DATEDIFF, and EXTRACT
- NULL handling and imputation with COALESCE
- Duplicate detection with DISTINCT, GROUP BY, HAVING, and ROW_NUMBER()
- Capstone 3: Clean Data Handoff
3 Hands-On SQL Intermediate Capstone Projects
Each part ends with a practical deliverable, so the intermediate concept is applied immediately in a realistic analytics workflow.
Multi-Step Enrollment Report
Build a structured enrollment report using nested and correlated subqueries, derived tables, and CTEs to break a larger analytical question into clean intermediate steps.
- Correlated & nested subqueries
- Derived tables
- CTEs
At-Risk Student Audit
Flag records that require attention using EXISTS checks, multi-condition CASE logic, conditional aggregation, and NULL-safe filtering across incomplete data.
- EXISTS / NOT EXISTS
- CASE logic
- NULL-safe filtering
Clean Data Handoff
Take messy data with inconsistent text, types, dates, missing values, and duplicates and prepare it for reporting entirely in SQL.
- String standardization
- Type & date conversion
- Duplicate detection
See How SQL Intermediate Is Taught
Lessons combine a clear concept explanation, a worked SQL example, a common beginner mistake, and hands-on practice in the course editor. Here is a short example from Part 3.
A NULL value represents missing or unknown data. It is not the same as zero or an empty string, so SQL uses special operators when you need to find missing values.
A common beginner mistake
WHERE email = NULL;
WHERE email IS NULL;
Worked example: replace a missing value
COALESCE returns the first non-NULL value it finds, making it useful for producing cleaner reports when fields are missing.
SQL Intermediate Course Format, Practice and Certificate
Frequently Asked Questions
SQL Beginner or equivalent comfort with SELECT, WHERE, JOIN and GROUP BY is recommended because SQL Intermediate builds directly on those skills.
The course covers advanced retrieval with subqueries, correlated subqueries, derived tables and CTEs; advanced filtering with EXISTS, ANY, ALL, CASE and NULL-safe logic; and SQL-based data cleaning with string, type, date and duplicate-handling techniques.
There are three hands-on capstone projects, one after each course part: Multi-Step Enrollment Report, At-Risk Student Audit, and Clean Data Handoff.
Yes. The built-in AI tutor provides guided hints and task support when learners get stuck.
Most learners can complete the three parts in about four to six weeks at a few hours per week. The course is self-paced.
Yes. Learners who complete the course receive a certificate of completion from the Canadian Institute of Artificial Intelligence (CiAI).
SQL Advance is the next course for learners who want more advanced analytics, performance, window-function and data-engineering patterns.
The course price shown on this page is US$15.99 per month. Use the single enrollment area at the top of the page to continue.
For current policy details, visit the DataSoSi FAQ page or Contact Us.
Yes. Visit the About CiAI page on DataSoSi to learn more about the Canadian Institute of Artificial Intelligence.
Continue Building Your SQL Skills
Meet the Creator of the Course
Learn from an educator who works across data science, machine learning, AI, analytics, and applied business problems.
Dr. Mark Lokanan
Professor · Data Scientist · Machine Learning & AI Specialist
Dr. Mark Lokanan is a professor at Royal Roads University and a Senior Machine Learning Engineer at Vedia. His work spans data science, machine learning, artificial intelligence, analytics, financial crime, and applied research. Drawing on both academic and industry experience, he designed the SQL Intermediate course to help learners move beyond foundational SQL into structured query reasoning, multi-step analysis, advanced filtering, data cleaning, and practical problem solving for analytics, business, and technology-focused roles.
