mole

A Nushell module for running SQL queries against named connections.

Define your MySQL/PostgreSQL connections in ~/.config/mole.yml, point at one, and get the result back as a Nushell table.

Why

mysql and psql CLIs are fine, but jumping between them, remembering host/port/credentials, and re-parsing their output every time gets old fast. mole is one verb (mole -q "..." -c connection) that picks the right driver based on the connection's config, runs the query, and hands back structured data the rest of your pipeline can use.

Requirements

Tool	Purpose
Nushell	Host shell
mysql	CLI used by the mysql driver
psql	CLI used by the postgres driver

You only need the CLI(s) for the drivers you actually use.

Installation

# clone into one of your NU_LIB_DIRS
let dest = [($env.NU_LIB_DIRS | first) mole] | path join
git clone git@github.com:lassoColombo/mole.git $dest

# use the module
use mole
mole --help

Configuration

Connections live in ~/.config/mole.yml. Each top-level key is a connection name; the value is a record matching the driver's expected fields.

my-postgres:
  driver: postgres
  user: alice
  password: hunter2
  host: db.example.com
  port: 5432
  database: app_production

my-mysql:
  driver: mysql
  user: alice
  password: hunter2
  host: mysql.example.com
  port: 3306
  database: app

Query files live under ~/.config/mole/ (recursively); reference them with -f path/to/query.sql.

Quick start

# run an inline query against a named connection
mole -c my-postgres -q 'select 1 as one'

# run a saved query file (path relative to ~/.config/mole/)
mole -c my-postgres -f reports/active-users.sql

# no -q and no -f opens $env.EDITOR on a temp file; runs whatever you save
mole -c my-postgres

# pick a default connection — subsequent bare calls use it
mole cfg set my-postgres
mole -q 'select now()'

# override fields ad-hoc without editing mole.yml
mole -c my-postgres -d app_staging -q 'select count(*) from users'

# write a destructive query? you'll get a yellow prompt unless you pass -y
mole -c my-postgres -q 'delete from sessions where expires_at < now()' -y

Commands

Command	Purpose
mole	Run a SQL query. Returns a table.
mole edit [queryfile]	Open the query directory (or one file) in $env.EDITOR.
mole cfg show [name]	Show all connections, or just one. Passwords masked unless -r.
mole cfg edit	Open ~/.config/mole.yml in $env.EDITOR.
mole cfg set [name]	Set the default connection. Picks interactively if no name given.
mole cfg translate-to <spec>	Render the connection list as config for another tool. See Translate-to.

mole flags

Flag	Short	Description
--query	-q	Inline SQL
--file	-f	Query file relative to ~/.config/mole/
--connection	-c	Named connection from mole.yml
--driver	-D	Override the driver (mysql or postgres)
--database	-d	Override the database
--port	-p	Override the port
--user	-u	Override the user
--host	-h	Override the host
--password	-P	Override the password
--yes	-y	Skip the dangerous-query prompt

If --query and --file are both omitted, mole opens $env.EDITOR on a temp .sql file and runs whatever you save.

Drivers

The driver map lives in drivers.nu. Each entry declares everything that varies per driver:

Field	Purpose
dangerous_keywords	Regex matched against the query to trigger the danger prompt
exec	Closure that runs the query and returns a complete record
parse	Closure that turns stdout into a table
list_databases / db_column / db_parser	Powers the --database completer

Built-in drivers:

Driver	CLI used	Output parsed as
mysql	mysql	TSV
postgres	psql --csv	CSV

Adding a driver is a matter of adding one entry to the registry in drivers.nu. The pipeline in mod.nu dispatches through the registry — no command code changes needed.

Translate-to

mole cfg translate-to <spec> returns a structured record matching the target tool's config schema. The user picks the encoding:

mole cfg translate-to sqls | to yaml | save -f ~/.config/sqls/config.yml

Supported specs:

Spec	Target
sqls	sqls language server (config.yml)

Dangerous-query prompt

Each driver carries a regex of statements that warrant a confirmation prompt — delete, drop, truncate, vacuum, flush, etc. The regex is driver-specific (postgres has vacuum and reindex; mysql has flush and kill). Pass -y to skip.

Module structure

mole/
├── mod.nu          # `main` (SQL runner), `edit`, re-exports cfg
├── cfg.nu          # connection-file management, translate-to
├── drivers.nu      # per-driver registry
└── completers.nu   # tab completers