SELECT

lessons/02-running-sqlite/A-getting-started.md → lessons/02-running-sqlite/A-installing-sqlite.md

@@ -1,3 +1,7 @@
+---
+title: "Installing SQLite"
+---
+
 What's great is that SQLite is probably already on your device. For Windows you may have to look for it but in MacOS and Linux, you should be able to get just run `sqlite3` and it should get you into a temporary session.
 
 ### Windows
@@ -24,7 +28,9 @@ If you need an alternative way to that (or need to get 3.46.0 specifically like
 
 ## Chinook
 
-We'll also be using [Chinook][chinook], a sample set of data. Please download the v1.4.5 Chinook_Sqlite.sql file as well.
+We'll also be using [Chinook][chinook], a sample set of data. Please download the v1.4.5 Chinook_Sqlite.sql file as well. I'll teach you how to use it in a bit, but suffice to say it's a dataset about movies that we'll use to have a quick intro to querying.
+
+## Start my server
 
 [download]: https://sqlite.org/download.html
 [windows]: https://sqlite.org/2024/sqlite-dll-win-x64-3460000.zip

lessons/02-running-sqlite/B-getting-started.md

@@ -0,0 +1,34 @@
+So now you have SQLite on your computer, let's just get the most basic session started. In your terminal type `sqlite3` (or whatever you're using to get as your alias for it.) You should see something like
+
+```bash
+SQLite version 3.46.0 2024-05-23 13:25:27
+Enter ".help" for usage hints.
+Connected to a transient in-memory database.
+Use ".open FILENAME" to reopen on a persistent database.
+sqlite>
+```
+
+Importantly, you'll see that we're connected to an in-memory database which means whatever we do in this session will be thrown away at the end. If you give a filename as an arguement (e.g. `sqlite3 my-data.db`) then it'll either open that file if it's exists or create it if it doesn't.
+
+## Dot Commands
+
+Type `.help` (note the leading period) into your session and hit enter. You should see a long list of possible commands you can run. The dot in front signifies that it's a dot command which are special administrative commands you can pass to SQLite to do something or get some information. This will be things like export your database to CSV, report potential bugs, open a file, etc. In other words, it's anything that isn't a query. The `.help` one is super useful for you to know if you need to be reminded of what's available.
+
+## Stopping SQLite
+
+Easiest way is CTRL + D. `.exit` is a valid dot command that works too.
+
+## Let' get it running
+
+Let's save everything to a file. I'll be saving my database to my desktop. Do the following.
+
+```bash
+cd ~/Desktop
+sqlite3 ./my-chinook.db
+
+## Inside sqlite
+.read ./Chinook_Sqlite.sql # or where-ever you downloaded this file
+.tables # you should the tables you imported from Chinook
+```
+
+Once you're here we're ready to start writing queries!

lessons/02-running-sqlite/meta.json

@@ -0,0 +1,4 @@
+{
+    "title": "Running SQLite",
+    "icon": "person-running"
+}

lessons/03-basic-sql/A-select.md

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+---
+title: "SELECT"
+---
+
+I like to learn SQL by doing rather than some contrived explanation of how grammar is broken down and blah blah blah. I like putting fingers on keyboards and seeing what happens when we do things. Once we start to experience what SQL can do for us then we can get a bit more fine grained in terms of what is doing what and why.
+
+> Note, this is meant to be a very quick intro to general SQL. I've taught [the Complete Intro to SQL][sql] before and it's more in-depth. This class uses Postgres but 95% of the grammar applies to both. I'll highlight where there's differences.
+
+## SELECT
+
+You should already have a database session open and have Chinook loaded. If not, look back at the previous lesson on how to do that.
+
+SELECT is the name of the "command" part of the query. It's what the command is going to do. In our case, we're going to be reading from the database which is a SELECT command.
+
+```sql
+SELECT * FROM Artist;
+```
+
+> Capitalization of SELECT and FROM isn't important. I usually do it out of habit because _everyone_ used to do it that way. It's not as common now and you'll see me do both.
+
+This will return about 275 rows from the database. We asked for _every_ single artist in the Artist table and we got it! The `*` just means that we wanted every single bit of info available for every artist. We if we only wanted _some_ of the info, we could ask for that like this.
+
+```sql
+SELECT name from Artist;
+```
+
+Notice the number is gone (which was the `ArtistId`) and we just have the name for each band. We could also ask for both like this
+
+```sql
+SELECT name, ArtistId from Artist;
+```
+
+Notice the columns came back in the order you ask for them too.
+
+> If you need to get the name of columns, `.schema <TABLE_NAME>` is helpful.
+
+## WHERE
+
+In this case, we're querying all rows without any filtering whatsoever. Some times this is useful but normally you have an idea of some subset of rows you want. Let's say we wanted to get the ID of one of my favorite bands, The Postal Service. How would we do that?
+
+```sql
+SELECT ArtistID FROM Artist WHERE name = 'The Postal Service';
+```
+
+> Very important you use single quotes here. Single quotes mean a value or string literal. Double quotes in SQL refer to he name of columns and so putting double quotes would not be valid SQL.
+
+This will just return `174` because that's all we asked for. Likewise we could do
+
+```sql
+SELECT name FROM Artist WHERE ArtistId = 174;
+```
+
+This one doesn't need quotes because it's the literal number 174.
+
+## LIKE
+
+Let's say you didn't know if The Postal Service was listed under "**The** Postal Service" or just "Postal Service". This is where LIKE can help.
+
+> SQLite does not have ILIKE, just LIKE. LIKE is case insensitive.
+
+```sql
+SELECT ArtistID FROM Artist WHERE name LIKE '%Postal Service';
+```
+
+This will match "The Postal Service", "Postal Service", "Definitely Postal Service" and anything that has text before "Postal Service". The `%` means "give anything that match 0 to many characters before this".
+
+You can use multiple too. Let's say we wanted to know every band that had "Orchestra" in the name. We can do that with
+
+```sql
+SELECT name FROM Artist WHERE name LIKE '%orchestra%';
+```
+
+Pretty cool, right?
+
+There are more comparator operators that you can discover for yourself as well
+
+```sql
+SELECT * FROM Artist WHERE ArtistId <= 10;
+```
+
+## LIMIT and OFFSET
+
+Sometimes you just want a few responses. I do this a lot to just see what's in a table.
+
+```sql
+SELECT * FROM Artist LIMIT 5;
+SELECT * FROM Artist LIMIT 5 OFFSET 5;
+SELECT * FROM Artist LIMIT 5 OFFSET 10;
+```
+
+This will allow you to page through results as well.
+
+## ORDER BY
+
+Frequently you will want to change how things are ordered as well.
+
+```SQL
+SELECT * FROM Artist ORDER BY name LIMIT 5;
+SELECT * FROM Artist ORDER BY name ASC LIMIT 5; -- Same as above query. ASC is implied if left out.
+SELECT * FROM Artist ORDER BY name DESC LIMIT 5;
+```

lessons/03-basic-sql/meta.json

@@ -0,0 +1,4 @@
+{
+    "title": "Basic SQL",
+    "icon": "code"
+}