This PR adds a command `join` for performing SQL-style joins on Nushell
tables:
```
〉join -h
Join two tables
Usage:
> join {flags} <right-table> <left-on> (right-on)
Flags:
-h, --help - Display the help message for this command
-i, --inner - Inner join (default)
-l, --left - Left-outer join
-r, --right - Right-outer join
-o, --outer - Outer join
Signatures:
<table> | join list<any>, <string>, <string?> -> <table>
Parameters:
right-table <list<any>>: The right table in the join
left-on <string>: Name of column in input (left) table to join on
(optional) right-on <string>: Name of column in right table to join on. Defaults to same column as left table.
Examples:
Join two tables
> [{a: 1 b: 2}] | join [{a: 1 c: 3}] a
╭───┬───┬───╮
│ a │ b │ c │
├───┼───┼───┤
│ 1 │ 2 │ 3 │
╰───┴───┴───╯
```
<table>
<tbody>
<tr>
<td><img width="400" alt="image"
src="https://user-images.githubusercontent.com/52205/224578744-eb9d133e-2510-4a3d-bd0a-d615f07a06b7.png"></td>
</tr>
</tbody>
</table>
# User-Facing Changes
Adds a new command `join`
# Tests + Formatting
```
cargo test -p nu-command commands::join
```
Don't forget to add tests that cover your changes.
- [x] `cargo fmt --all -- --check` to check standard code formatting
(`cargo fmt --all` applies these changes)
- [x] `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- [x] `cargo test --workspace` to check that all tests pass
# After Submitting
- [ ] If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
---------
Co-authored-by: Reilly Wood <reilly.wood@icloud.com>
