From SELECT to JOIN: A 7-Day SQL Practice Plan for December

December is chaotic, loud, and full of excuses not to learn anything. But with one quick diagnostic and a single course you actually enjoy, you can still make real SQL progress before the year wraps up.

December is intense. You’re juggling year-end tasks, holiday prep, shopping, cleaning, family logistics, and maybe even looking for a new job because your current one (the second one this year) is falling apart.

Here’s something you can fit into December: a simple, flexible SQL practice plan. It’s called a 7-day plan, but let’s be real: these are seven sessions you can spread across the entire month without guilt, panic, or performance anxiety.

Day 1: Take the December Monthly SQL Practice Course

Start with the Monthly SQL Practice – December 2025. This is your official SQL diagnostic. The moment you finish, you’ll know exactly which direction to go:

• JOINs made you want to throw your laptop
• GROUP BY made you question your life
• filtering logic betrayed you
• or it all fell apart equally

Once you see the weak spots, your path is clear.

The Next Sessions: Pick ONE Long Course and Stick With It

December is not the time to pretend you’ll do three courses at once. Pick one long LearnSQL.com course and stay loyal to it.

If JOINs Are Your Main Problem

👉 SQL JOINs course

The SQL JOINs course is designed for people who already know how to write basic single-table queries, but struggle when data lives across multiple tables.

It covers every major JOIN type — INNER, LEFT, RIGHT, FULL (and even CROSS) — so you finally get to see what each does in practice.

Beyond that, it dives into multi-table JOINs, self-joins (yes — joining a table with itself), non-key JOINs (joining on columns that aren’t primary/foreign keys), and “non-equi” JOINs (when you join using conditions other than equality).

That means you’ll get practice with queries like: combining several tables in one request, linking a table to itself (for example, “employees and their managers”), or joining tables based on non-typical keys — all scenarios that show up in real-life databases.

With 93 interactive exercises, this course doesn’t just teach — it forces you to use JOINs until they stop being scary.

If you follow this path this December, by the end of it you’ll actually understand what JOINs do, why the heck your query exploded into 10,000 rows, and how to fix it — no more accidental Cartesian-product disasters.

If GROUP BY Is Your Main Problem

👉 SQL GROUP BY Practice course

If the December Monthly SQL Practice Course made it clear that aggregations, summaries and grouped queries are what break your flow — then GROUP BY is your target. GROUP BY isn’t a fancy add-on. It’s one of the most fundamental tools when you want to move from “show me every row” to “show me useful business-level insights.”

The SQL GROUP BY Practice course is built exactly for this. It gives you 120+ hands-on exercises using real-world datasets — from video-games and retail sales, to university data, blog traffic or sports results. The course focuses on teaching you how to group rows that share a common value (or combinations of values), and then apply aggregate functions such as COUNT(), SUM(), AVG(), MIN(), MAX().

You’ll get familiar with grouping by a single column, grouping by multiple columns, and combining aggregates with conditions. The course also introduces you to filtering grouped data using HAVING, which differs from WHERE — because it works after aggregation. That means you can build queries like “find all customers with more than 10 purchases” or “show total sales by region, but only for regions with average order value above X.”

Because the exercises use realistic, varied datasets (games, sales, students, traffic, etc.), you don’t just get toy examples — you practice on data that feels like what you’d see in real-life analytics or business reporting. By the end of the course you should be able to: summarize data, compute totals, averages, counts; group by different combinations of columns; filter aggregated results properly; and write reports or analytics queries that actually make sense.

If GROUP BY — not JOINs — is what messes up your queries, this course gives you a clean, practical path to fix that.

Other Courses: Choose One That Matches Your Taste and Stick with It

If you don’t want to focus only on JOINs or GROUP BY — or if you want a more general, practice-driven path — LearnSQL offers several practice courses built around realistic datasets. Each has its own flavour and use-case. Here are the main options:

👉 SQL Practice Set

This is the most general, “all-in-one” practice course: 88 interactive exercises ranging from basic SELECT queries to more advanced tasks involving subqueries, grouping, ordering, JOINs, and aggregation.

It’s a perfect choice if you’ve already got the basics down and want a broad mix of SQL challenges — in different styles and difficulty levels — without committing to a specific data domain. It helps reinforce foundational skills across the board: selects, filters, aggregate functions (COUNT, SUM, AVG), grouping and ordering, various JOINs, and subqueries.

If you don’t know exactly what you’re weak at — or if you want a balanced approach — this is the safest pick. It’s like a gym for SQL: varied exercises, constant repetition, and good for building overall strength.

👉 Basic SQL Practice: A Store

This course uses a retail-store dataset (products, sales, customers, inventory etc.). It’s ideal if you’re interested in business analytics, e-commerce, retail data, or working with sales/inventory databases. Practicing on a “store” context can help you learn queries relevant for real-world business use cases: orders history, customer segmentation, product performance — tasks that marketers, product managers, or analysts often face.

For someone with background in e-commerce marketing and PIM / e-commerce consulting, this course might align very well with your domain. You’ll practice SQL in a context similar to what you deal with professionally — which helps link learning with practical business insights.

👉 SQL Practice: University

This uses a fictional university database (students, lecturers, courses, enrollments, grades etc.). It includes a broad set of SQL tasks: selects, joins, ordering, grouping, subqueries — basically common database operations, but in an academic context. 156 interactive exercises make it a full and solid training ground.

It’s especially good if you prefer structured data like enrolments, courses, relationships between tables — or simply want a “neutral” context to practice SQL without business-specific noise. For example: analyzing students’ data, courses per semester, average grades, lecturers’ load, etc. Good for generalizing SQL logic beyond retail or marketing.

👉 Basic SQL Practice: Run Track Through Queries!

This one is for sports and performance data fans. The dataset comes from track competitions, athlete results, race categories, maybe historical championships. It’s a fun and dynamic alternative: you’ll practice SQL through queries like “top performers,” “average times,” “rankings by country,” or “performance trends over time.”

It’s a nice fit if you get bored of business or e-commerce datasets — a fresh context can make practicing SQL more enjoyable. Also good if you like sports analytics or want to see how queries work with event-style data (dates, times, results, categories).

👉 Basic SQL Practice: Blog & Traffic Data

This course uses a dataset reflecting blog posts, traffic data, user activity, maybe content publishing, views, engagement metrics — think blog, media site, online publication. Great for anyone interested in content analytics, user behaviour, marketing analytics, or web data.

If your background blends marketing, e-commerce and digital analytics, this course might feel relevant and even fun. You could practice queries like “top 10 most viewed articles,” “user engagement by time,” “traffic by referrer,” or “conversion rate per post” — analytics useful in real digital marketing work.

Once you pick one, stick with it for the rest of the month. The consistency helps — each course gives many exercises, repeated exposure to key SQL patterns, and builds fluency gradually.

Why This Works

Because December is already wild. People are running around doing chores, organising families, buying gifts, pretending to rest, and trying not to burn anything in the oven.

Seven focused SQL sessions — spread however you want — is completely achievable.

Keep the Momentum Into 2026

If December is your warm-up, January can be your momentum month. The easiest way to stay consistent is to unlock everything once: the All Forever SQL Plan.

You get lifetime access to:

• every SQL course
• every monthly practice course
• every future update

No renewals. No limits. No “which course should I buy next?”

Just you, your laptop, and hopefully fewer December chores.