SQL
The language for querying and managing data in a relational database.
1. Introduction to SQL
How SQL talks to a database made of tables, rows, and columns — the students table every later lesson builds on.
2. SELECT
Choosing which columns to retrieve — the keyword that starts nearly every SQL query you'll ever write.
3. WHERE
Filtering rows with a condition — and how AND/OR combine multiple conditions together.
4. ORDER BY
Sorting results ascending or descending — and the default you get if you forget to specify.
5. INSERT INTO
Adding a new row to a table — matching column names to values in the same order.
6. UPDATE & DELETE
Changing existing rows, and removing them — and why the WHERE clause is the single most important part of both.
7. JOIN
Combining rows from two related tables based on a matching column.
8. Aggregate Functions
COUNT, SUM, AVG, MIN, and MAX — summarizing many rows into one value, and how GROUP BY changes that from one summary to many.