graphile/discussion

A temporary forum to discuss ideas.

discussion's Issues

CLI: `postgraphile copy`

I'm submitting a ...

• bug report
• feature request
• question

I think a great addition to the CLI (and library) would be a copy command with the following semantics:

Usage: postgraphile copy

Options:
  --table <string>                           the PostgreSQL table name to copy from/to
  -c, --connection <string>                  the PostgreSQL database name or connection string. If omitted, inferred from environmental variables (see https://www.postgresql.org/docs/current/static/libpq-envars.html). Examples: 'db', 'postgres:///db', 'postgres://user:password@domain:port/db?ssl=1'
  -s, --schema <string>                      a Postgres schema to be introspected. Use commas to define multiple schemas

This utility would be a lightweight wrapper around native PostgreSQL COPY functionality. Importantly, JSON documents read from STDIN (or written to STDOUT) would be transformed through the same inflector logic postgraphile normally uses when serializing/deserializing rows to/from GraphQL queries.

Example CLI Usage:

# export data to a file as JSON
postgraphile copy -s public --table authors > authors.json

# import JSON data from a file
cat authors.json | postgraphile copy -s public --table authors

Example Library Usage:

import * as fs from 'fs';
import { createReadStream, createWriteStream } from 'postgraphile';

// export data
createReadStream(pgConfig, { schema, table })
  .pipe(fs.createWriteStream('./authors.json'));

// import data
fs.createReadStream('./authors.json')
  .pipe(createWriteStream(pgConfig, { schema, table });