eloquent code

There are many ways to install Node, but for the latest version you cannot use apt install or apt-get install.

The best way is to use the Node Version Manager (nvm) to install Node.

Note that there is no Ubuntu package for nvm and nvm is not a regular binary, but rather a shell function.

Note also that nvm is not meant to be used with sudo ! The install will be for your current regular user.

Before installing: make sure to have a .bash_profile file in your home directory.

The following steps will install nvm and node (and hence npm).

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash

Reload your terminal.

Find the latest version listed by the following command:

nvm ls-remote

At the time of writing the latest was 9.5.0, so:

nvm install 9.5.0

nvm use 9.5.0

Check that the latest versions of node and npm are ready:

node -v

npm -v

PostGraphQL will provide GraphQL access automatically to your data stored in a PostgreSQL database.

Assuming we have PostgreSQL installed already with at least one database created but we don’t have Node yet – install Node Version Manager (nvm), the latest version of Node.js and PostGraphQL:

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash

nvm install node 

npm install -g postgraphql

Assuming we have a database called my_database and a user my_database_usr, in one terminal run the PostGraphQL server:

postgraphql -c "postgres://my_database_usr:password@localhost:5432/my_database"

The server should be running on port 5000 on localhost.

Note: make sure you have a PostgreSQL version newer than 9.4 or else you will see this error:

error: function pg_catalog.pg_relation_is_updatable(oid, boolean) does not exist

In another terminal, send an HTTP POST request to see what data is available:

curl -X POST "http://localhost:5000/graphql" -H "Content-type: application/json" -d "{\"query\": \"{__schema{types{name}}}\"}"

The following example query assumes a table “books” with a field “title” in my_database. The cURL command is below:

curl -X POST "http://localhost:5000/graphql" -H "Content-type: application/json" -d "{\"query\": \"{allBooks{edges{node{title}}}}\"}"

In a browser you can also explore the data with GraphiQL at:

http://localhost:5000/graphiql

 

A list of useful vim (vi) editing commands.

 

cc

Replace entire line: delete and enter input mode.

:r filename

Paste contents of filename into current file.

:x

Write file and exit. Short for :wq