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  • License MIT

Given a Knex select object will provide a hyrdated object using promises.

Package Exports

  • knexnest

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (knexnest) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

KnexNest

Build Status Coverage Status

Takes a Knex.js select query object and hydarates a list of nested objects using the NestHydration npm module.

This can be simply accomplished without this library by doing

return knex.select(...)
    .then(NestHydrationJS.nest)
    .then(function (data) {
        ...
    })
;

However Postgres limits column names to 63 characters and this becomes a problem when trying to nest objects several deep using NestHydration. A column name such as _activeUser_purchases__product_originalManufacturer_logoSmall_url would be too long and would cause nasty behavior. This module handles this problem by mapping long names to shorter ones and then returning them with a structPropToColumnMap object passed to NestHydration.

Example Usage

var Knex = require('knex');
var knexnest = require('knexnest');

var knex = Knex({
    client: 'postgres',
    connection: process.env.DATABASE_URL
});

var sql = knex
    .select(
        'c.id    AS _id',
        'c.title AS _title',
        't.id    AS _teacher_id',
        't.name  AS _teacher_name',
        'l.id    AS _lesson__id',
        'l.title AS _lesson__title'
    )
    .from('course AS c')
    .innerJoin('teacher AS t', 't.id', 'c.teacher_id')
    .innerJoin('course_lesson AS cl', 'cl.course_id', 'c.id')
    .innerJoin('lesson AS l', 'l.id', 'cl.lesson_id')
;
knexnest(sql).then(function (data) {
    result = data;
});
/* result should be like:
[
    {id: '1', title: 'Tabular to Objects', teacher: {id: '1', name: 'David'}, lesson: [
        {id: '1', title: 'Defintions'},
        {id: '2', title: 'Table Data'},
        {id: '3', title: 'Objects'}
    ]},
    {id: '2', title: 'Column Names Define Structure', teacher: {id: '2', name: 'Chris'}, lesson: [
        {id: '4', title: 'Column Names'},
        {id: '2', title: 'Table Data'},
        {id: '3', title: 'Objects'}
    ]},
    {id: '3', title: 'Object On Bottom', teacher: {id: '1', name: 'David'}, lesson: [
        {id: '5', title: 'Non Array Input'},
    ]}
]
*/