Module 4: SQL for Data Analysis
- Write SELECT, WHERE, GROUP BY, and ORDER BY queries
- Join two or more tables with JOIN
- Use aggregate functions like COUNT, SUM, and AVG
SQL (Structured Query Language) is how analysts talk to databases, and it remains one of the most requested skills in data job postings worldwide, including remote roles open to candidates anywhere with reliable internet. You will learn the anatomy of a query: SELECT to choose columns, FROM to name the table, WHERE to filter rows, GROUP BY to aggregate, and ORDER BY to sort results. You will then learn JOIN, which combines rows from two tables based on a shared key, for example matching a customers table to an orders table by customer_id, and practice aggregate functions (COUNT, SUM, AVG, MIN, MAX) to answer questions like "what is the average order value per region?"
1. To combine a customers table and an orders table by matching customer_id in both, you would use:
2. In SQL, which clause filters rows before any grouping happens?
3. Which SQL function returns the number of rows that match a condition?