DailyRNG

SQL & Databases

SQL & Databases

Every lesson in order, step by step. No difficulty tiers. Just follow the arrows.

15 lessons, about 26 min of reading

1

The file that is not a file →

Step 1 · Basic

2

Asking a question →

Step 2 · Basic

3

Only the rows that match →

Step 3 · Basic

4

Stitching two tables →

Step 4 · Basic

5

Adding rows safely →

Step 5 · Basic

6

Changing one row →

Step 6 · Basic

7

Counting instead of listing →

Step 7 · Basic

8

Putting rows in order →

Step 8 · Advanced

9

Counting per group →

Step 9 · Advanced

10

Computing inside the query →

Step 10 · Advanced

11

The blank that is not zero →

Step 11 · Advanced

12

Making lookups fast →

Step 12 · Advanced

13

Tables that vouch for each other →

Step 13 · Master

14

A saved question →

Step 14 · Master

15

All of it or none of it →

Step 15 · Master