OData V4 Service modules - PostgreSQL Connector

Service OData v4 requests from a PostgreSQL data store for Objection.js (knex.js) ORM for Node.js

This is a modified and specific version of odata-v4-pg. As work continues, this library will be moved to something more appropriately named.

2.0 Breaking Changes (potential if you rely on case sensitive)

OData pattern matching operators [contains, substringof, startswith, endswith] have been changed to resolve to ILIKE or ~* from LIKE: |Operator | PG Operator | Sample | | ----------- | --------------| ------- | | contains | ~* (regex) | "status" ~* 'jen' | | substringof | ILIKE | "status" ILIKE '%jen%' | | startswith | ILIKE | "status" ILIKE 'jen%' | | endswith | ILIKE | "status" ILIKE '%jen' |

Contains with regex can perform a little better than ILIKE, your milage may certainly very.

Synopsis

The OData V4 PostgreSQL Connector provides functionality to convert the various types of OData segments into SQL query statements suitable for Objection / knex.js raw() where clause

Snake_Case conversion

This library assumes your Nest/Objection/knex are leveraging Postgre snake_case for table names. As such, OData queries for camelCase properties will be converted to snake_case automatically.

Named bindings

In knex.js - Named bindings such as :name are interpreted as values and :name: interpreted as identifiers. Named bindings are processed so long as the value is anything other than undefined.

As such, odata-v4-pg will set placeholders as :0 (index value) for all placeholders. This helps alleviate issues for createDate eq null statements, that are absent of any placeholders. With named bindings, this does not present a problem.

Potential usage scenarios

• Nest.js & Objection.js (or direct Knex.js) library helper

See the (index.spec.ts)[./src/lib/index.spec.ts] for sanity tests

Usage as server - TypeScript

import { createFilter } from 'odata-v4-pg'

//example request/query filter:  
const { raw } = require('objection');
const sDay = moment.utc().startOf('day').toISOString();
const query = { $filter: `(startDate ne null or startDate ge '${moment.utc().startOf('day').toISOString()}')`, $expand: '' };
const filter = createFilter(query.$filter); // map $filter OData to pgSql statement

await Person
  .query()
  .where(raw(filter.where, filter.parameterObject()));
}

Supported OData segments

• $filter
• $select
• $skip
• $top
• $orderby
• $expand

NPM package

Change the version in your package.json or use npm version . npm version patch or npm version prerelease

After changing the version number in your package.json, run npm publish to publish the new version to NPM.

npm install will install the latest version in the NPM repository.

Complete sequence

npm run build
<commit changes>
npm version prerelease
git push
git push --tags 
npm publish

Other

Build Error: odata-v4-server

The latest version of odata-v4-server shows a build error as:

node_modules/odata-v4-server/build/lib/processor.d.ts:20:22 - error TS2415: Class 'ODataProcessor' incorrectly extends base class 'Transform'.
  Property '_flush' is protected in type 'ODataProcessor' but public in type 'Transform'.

One workaround is TypeScript can build project if pass option tsc --skipLibCheck, so this was added to the build scripts. Ref this github issue