sqlite-reader/README.md

This is a starting point for Rust solutions to the
["Build Your Own SQLite" Challenge](https://codecrafters.io/challenges/sqlite).

In this challenge, you'll build a barebones SQLite implementation that supports
basic SQL queries like `SELECT`. Along the way we'll learn about
[SQLite's file format](https://www.sqlite.org/fileformat.html), how indexed data
is
[stored in B-trees](https://jvns.ca/blog/2014/10/02/how-does-sqlite-work-part-2-btrees/)
and more.

**Note**: If you're viewing this repo on GitHub, head over to
[codecrafters.io](https://codecrafters.io) to signup for early access.

# Passing the first stage

CodeCrafters runs tests when you do a `git push`. Make an empty commit and push
your solution to see the first stage fail.

```sh
git commit --allow-empty -m "Running tests"
git push origin master
```

You should see a failure message that says it expected "number of tables: <n>"
to be present.

Go to `src/main.rs` and uncomment the `.dbinfo` command implementation. Commit
and push your changes to pass the first stage:

```sh
git add .
git commit -m "pass the first stage"
git push origin master
```

Time to move on to the next stage!

# Running Your Program Locally

1. Ensure you have `cargo (1.54)` installed locally
1. Run `./your_sqlite3.sh` to run your program, which is implemented in
   `src/main.rs`. This command compiles your Rust project, so it might be slow
   the first time you run it. Subsequent runs will be fast.
1. Commit your changes and run `git push origin master` to submit your solution
   to CodeCrafters. Test output will be streamed to your terminal.

# Sample Databases

To make it easy to test queries locally, we've added a sample database in the
root of this repository: `sample.db`.

This contains two tables: `apples` & `oranges`. You can use this to test your
implementation for the first 6 stages.

You can explore this database by running queries against it like this:

```sh
$ sqlite3 sample.db "select id, name from apples"
1|Granny Smith
2|Fuji
3|Honeycrisp
4|Golden Delicious
```

There are two other databases that you can use:

1. `superheroes.db`:
   - This is a small version of the test database used in the table-scan stage.
   - It contains one table: `superheroes`.
   - It is ~1MB in size.
1. `companies.db`:
   - This is a small version of the test database used in the index-scan stage.
   - It contains one table: `companies`, and one index: `idx_companies_country`
   - It is ~7MB in size.

These aren't included in the repository because they're large in size. You can
download them by running this script:

```sh
./download_sample_databases.sh
```

If the script doesn't work for some reason, you can download the databases
directly from
[codecrafters-io/sample-sqlite-databases](https://github.com/codecrafters-io/sample-sqlite-databases).