Description
Coding
SQL & Databases
Learn to query and organize data with 32 practical SQL lessons, from your first SELECT to joins, transactions, and analytical reports.
Read, filter, summarize, and update sample tables.
- 1
Your first SQL query
Return values with SELECT and name the result columns.
12 min
- 2
Tables, rows, and columns
Read selected fields from a table and identify rows with keys.
12 min
- 3
Filtering rows
Use comparisons to select rows that meet a condition.
12 min
- 4
Combining conditions
Combine filters with AND, OR, NOT, and parentheses.
12 min
- 5
Sorting and limiting results
Choose a deterministic order before taking a subset.
12 min
- 6
Missing values and NULL
Test for missing values with IS NULL instead of equality.
12 min
- 7
Sets, ranges, and distinct values
Use IN, BETWEEN, and DISTINCT for common filters.
12 min
- 8
Text patterns
Find simple text patterns and understand wildcard matching.
12 min
- 9
Expressions and aliases
Calculate readable results while controlling numeric division.
12 min
- 10
Aggregate functions
Summarize rows with COUNT, SUM, and AVG.
12 min
- 11
Grouping rows
Produce one aggregate result per group.
12 min
- 12
Writing sample data
Insert, update, and delete rows in an isolated database.
12 min