I'm starting using Node.JS, bookshelf.js and bookshelf-pagemaker.
My database contain 2 tables :
- Asset with 3 main rows (idasset, name, idarrangement)
- Arrangement_details with 2 main row (idarrangement_details, material)
I would like get all Asset where material = 2 for example.
The Asset model :
var AssetsCollection = DB.Model.extend({
tableName: 'assets',
idAttribute: 'idassets',
arrangementdetails: function () {
return this.belongsTo(ArrangementDetail, 'idarrangement_details');
}
});
I've tried this code but it crash because arrangementdetails is not joined.
var pm = require('bookshelf-pagemaker')(DB);
pm(AssetsCollection.AssetsCollection)
.forge()
.limit(req.params.limit)
.offset(req.params.page)
.query(function(qb){
qb.where('Arrangement_details.material', '=', 4)
})
.paginate({request: req, withRelated: ['arrangementdetails'])
.end({})
.then(function (results) {
callback(null, {code: 200 , res: results});
});
It's possible to do that ?
Regards,
DarKou
you need to join the tables in order to search a related one. without seeing your table structure this will be somewhat a shot in the dark, but you should use a join in the query callback along with your where similar to the following. to be clear there is no functional issue with either bookshelf or pagemaker with what you are trying to accomplish.
it appears you have 2 tables, with the following
table: assets, idAttribute: idassets
table: Arrangement_details, idAttribute: idarrangement_details
var pm = require('bookshelf-pagemaker')(DB);
pm(AssetsCollection.AssetsCollection)
.forge()
//.limit(req.params.limit) -- not needed as you are already passing req to paginate
//.offset(req.params.page) -- not needed as you are already passing req to paginate
.query(function(qb){
qb.join('Arrangement_details', 'Arrangement_details.idarrangement_details', '=', 'assets.idarrangement_details')
.where('Arrangement_details.material', '=', 4);
})
.paginate({request: req, withRelated: ['arrangementdetails'])
.end()
.then(function (results) {
callback(null, {code: 200 , res: results});
});
i would however encourage you use less confusing names for your tables/fields similar like the following where id is the idAttribute for both and details_id is the foreign key for the belongsTo relationship
var AssetsCollection = DB.Model.extend({
tableName: 'assets',
idAttribute: 'id',
arrangementDetails: function () {
return this.belongsTo(ArrangementDetail, 'details_id');
}
});
var ArrangementDetail = DB.Model.extend({
tableName: 'arrangement_details',
idAttribute: 'id'
});
var pm = require('bookshelf-pagemaker')(DB);
pm(AssetsCollection.AssetsCollection)
.forge()
.query(function(qb){
qb.join('arrangement_details', 'arrangement_details.id', '=', 'assets.details_id')
.where('arrangement_details.material', '=', 4);
})
.paginate({request: req, withRelated: ['arrangementDetails'])
.end()
.then(function (results) {
callback(null, {code: 200 , res: results});
});
Related
Im trying to get iterate the results array variable.
I am able to get the array values inside the function, but when i try to log it outside it shows null.
Wen i googled few posts, i see that forEach was not recommended, suggested was for loop, i tried even that and i get null for result.
What is the issue in cursor.forEach()...
router.get('/getlist', function(req, res, handleError) {
client.connect('mongodb://localhost', function(err, client) {
if (err) throw err;
var db = client.db('angular-demo');
var collection = db.collection("api_details");
var query = {};
var cursor = collection.find(query);
var results = new Array();
var results = cursor.forEach(
function(result) {
return result;
console.log("insert")
console.log(results);
}
);
console.log("append")
console.log(results); //results here shows null
});
});
Log result:
append
[]
insert
[ { _id: 5a6867c8e54f6120709eabc5,
app_id: 'CaseRegistration',
description: 'API to register cases in the system',
cost_per_usage: '0.5',
__v: 0 } ]
insert
[ { _id: 5a6867c8e54f6120709eabc5,
app_id: 'CaseRegistration',
description: 'API to register cases in the system',
cost_per_usage: '0.5',
__v: 0 },
{ _id: 5a6867fde54f6120709eabc6,
app_id: 'CheckCreation',
description: 'CREs create the case with minimal data and assigns it to case initiation team to create checks',
cost_per_usage: '1',
__v: 0 } ]
If you want to grab results from find you can use toArray
cursor.toArray(function (error, documents) {
console.log(documents)
})
// or
cursor.toArray().then(function (documents) {
console.log(documents)
})
// or in async function
const documnets = await cursor.toArray()
or if you need to transform them somehow use map
It's not relevant if you use forEach or for loop in this case. The results variable isn't being populated because you're trying to populate it with the return result from the forEach which doesn't return anything useful.
What you want to do, is just iterate over the results, and fill the results array while iterating.
Something more like this :
var results = [];
cursor.forEach(
function(result) {
results.push(result);
}
);
console.log(results); // This should be populated now
I am trying to build an app involves posts and tags for posts. For these I have a post, tags and post_tag table. tags has the tags I have defined before hand and in somewhere in the app is suggested to the user on the front-end. post_tag table holds the post and tag ids as pairs on each row.
I use express.js and postgreql and pg-promise.
As far as I know I need a transactional query(ies) for a create post operation.
Also I need a mechanism to detect if a tag was not in tags table when the user created the post, so that I can insert it on the fly, and I have a tag_id for each tag that is neccessary to use in insertion of the post_id and tag_id into post_tag table. Otherwise, I will have a foreign key error since I need to post_tag table's columns post_id and tag_id to reference posts and tags table id columns, respectively.
Here is the url function I use for this I have used so far unsuccessful:
privateAPIRoutes.post('/ask', function (req, res) {
console.log('/ask req.body: ', req.body);
// write to posts
var post_id = ''
var post_url = ''
db.query(
`
INSERT INTO
posts (title, text, post_url, author_id, post_type)
VALUES
($(title), $(text), $(post_url), $(author_id), $(post_type))
RETURNING id
`,
{
title: req.body.title,
text: req.body.text,
post_url: slug(req.body.title),
author_id: req.user.id,
post_type: 'question'
} // remember req.user contains decoded jwt saved by mw above.
)
.then(post => {
console.log('/ask post: ', post);
post_id = post.id
post_url = post.post_url
// if tag deos not exist create it here
var tags = req.body.tags;
console.log('2nd block tags1', tags);
for (var i = 0; i < tags.length; i++) {
if (tags[i].id == undefined) {
console.log('req.body.tags[i].id == undefined', tags[i].id);
var q1 = db.query("insert into tags (tag) values ($(tag)) returning id", {tag: tags[i].label})
.then(data => {
console.log('2nd block tags2', tags);
tags[i].id = data[0].id
// write to the post_tag
db.tx(t => {
var queries = [];
for (var j = 0; j < tags.length; j++) {
var query = t.query(
`
INSERT INTO
post_tag (post_id, tag_id)
VALUES
($(post_id), $(tag_id))
`,
{
post_id: post_id,
tag_id: tags[j].id
}
)
queries.push(query);
}
return t.batch(queries)
})
.then(data => {
res.json({post_id: post_id, post_url: post_url})
})
.catch(error => {
console.error(error);
})
})
.catch(error => {
console.error(error);
});
}
}
})
.catch(error => {
console.error(error);
})
});
The main problem you have - you can't use the root-level db object inside a task or transaction. Trying to create a new connection while inside a transaction breaks the transaction logic. You would need to use t.tx in such cases. However, in your case I don't see that you need it at all.
corrected code:
privateAPIRoutes.post('/ask', (req, res) => {
console.log('/ask req.body: ', req.body);
db.tx(t => {
return t.one(
`
INSERT INTO
posts (title, text, post_url, author_id, post_type)
VALUES
($(title), $(text), $(post_url), $(author_id), $(post_type))
RETURNING *
`,
{
title: req.body.title,
text: req.body.text,
post_url: slug(req.body.title),
author_id: req.user.id,
post_type: 'question'
} // remember req.user contains decoded jwt saved by mw above.
)
.then(post => {
console.log('/ask second query: post[0]: ', post);
console.log('/ask second query: tags: ', req.body.tags);
console.log('/ask second query: tags[0]: ', req.body.tags[0]);
// the key piece to the answer:
var tagIds = req.body.tags.map(tag => {
return tag.id || t.one("insert into tags(tag) values($1) returning id", tag.label, a=>a.id);
});
return t.batch(tagIds)
.then(ids => {
var queries = ids.map(id => {
return t.one(
`
INSERT INTO post_tag (post_id, tag_id)
VALUES ($(post_id), $(tag_id))
RETURNING post_id, tag_id
`,
{
post_id: post.id,
tag_id: id
}
)
});
return t.batch(queries);
});
});
})
.then(data => {
// data = result from the last query;
console.log('/api/ask', data);
res.json(data);
})
.catch(error => {
// error
});
});
The key here is simply to iterate through the tag id-s, and for the ones that are not set - use an insert. Then you settle them all by passing the array into t.batch.
Other recommendations:
You should use method one when executing an insert that returns the new record columns.
You should use try/catch only once there, on the transaction. This is relevant to how to use promises, and not just for this library
You can place your queries into external SQL files, see Query Files
To understand conditional inserts better, see SELECT->INSERT
I'm trying to get users count belongs to specific company.
Here is my model;
var Company = Bookshelf.Model.extend({
tableName: 'companies',
users: function () {
return this.hasMany(User.Model, "company_id");
},
users_count : function(){
return new User.Model().query(function(qb){
qb.where("company_id",9);
qb.count();
}).fetch();
},
organization: function () {
return this.belongsTo(Organization.Model, "organization_id");
}
});
method "users" works very well, no problem.
method "users_count" query works well, but cant get value to "company" model.
in routes, i'm using bookshelf models like this;
new Company.Model({id:req.params.id})
.fetch({withRelated:['users']})
.then(function(model){
res.send(model.toJSON())
})
.catch(function(error){
res.send(error);
});
How should i use users_count method, i'm kinda confused (probably because of promises)
Collection#count()
If you upgrade to 0.8.2 you can use the new Collection#count method.
Company.forge({id: req.params.id}).users().count().then(userCount =>
res.send('company has ' + userCount + ' users!');
);
Problem with your example
The problem with your users_count method is that it tries to make Bookshelf turn the result of your query into Models.
users_count : function(){
return new User.Model().query(function(qb){
qb.where("company_id",9);
qb.count();
}).fetch(); // Fetch wanted an array of `user` records.
},
This should work in this instance.
users_count : function(){
return new User.Model().query()
.where("company_id",9)
.count()
},
See relevant discussion here.
EDIT: How to get this in your attributes.
Maybe try something like this:
knex = bookshelf.knex;
var Company = bookshelf.Model.extend({
tableName: 'companies',
initialize: function() {
this.on('fetching', function(model, attributes, options) {
var userCountWrapped = knex.raw(this.getUsersCountQuery()).wrap('(', ') as user_count');
options.query.select('*', userCountWrapped);
}
}
users: function () {
return this.hasMany(User.Model, "company_id");
},
getUsersCountQuery: function() {
return User.Model.query()
.where("company_id",9)
.count();
}
organization: function () {
return this.belongsTo(Organization.Model, "organization_id");
}
});
Check out the bookshelf-eloquent extension. The withCount() function is probably what you are looking for. Your code would look something like this:
let company = await Company.where('id', req.params.id)
.withCount('users').first();
User.collection().query(function (qb) {
qb.join('courses', 'users.id', 'courses.user_id');
qb.groupBy('users.id');
qb.select("users.*");
qb.count('* as course_count');
qb.orderBy("course_count", "desc");
})
I've got two Bookshelf models in a many-to-many relationship and I'd like to have timestamps updated when I'm attaching or detaching some relations.
Here's my models:
var Video = Bookshelf.Model.extend({
tableName: 'video',
program: function(){
return this.belongsToMany(Bookshelf.model('Program'), 'programvideo', 'videoId', 'programId');
}
});
var Program = Bookshelf.Model.extend({
tableName: 'program',
videos: function(){
return this.belongsToMany(Bookshelf.model('Video'), 'programvideo', 'programId', 'videoId');
}
});
Everything works fine when I'm using
prgm.videos().attach(videos);
But is there any way to add timestamps to this relation? Do I need to define a pivot model in Bookshelf?
Thanks
Well, you could easily make a pivot model, create in migrations timestamps and enable timestamps in the model, and everything would work seamless!
However, if you'd like to solve this without additional model, you have to define firstly withPivot in models, e.g.:
var Stations = bookshelf.Model.extend({
tableName: 'stations',
stationsRoutes: function() {
return this.belongsToMany(Routes, 'stations_routes').withPivot('time');
}
});
var Routes = bookshelf.Model.extend({
tableName: 'routes',
stationsRoutes: function() {
return this.belongsToMany(Stations, 'stations_routes').withPivot('time');
}
});
Then, each time when you attach data, you have to call updatePivot, e.g.:
router.get('/updatePivot/:id', function(req, res) {
new Routes({
'id': req.params.id
}).fetch({
withRelated: ['stationsRoutes']
}).then(function(result) {
result.stationsRoutes().attach({
station_id: 3
}).then(function() {
result.stationsRoutes().updatePivot({
'time': '09:09'
}/*, {
query: function(qb) {
qb.where({
'id': 8
});
}
}*/).then(function() {
result.load('stationsRoutes').then(function(result_reloaded){
res.json(result_reloaded);
});
});
});
});
});
I've commented the piece of code where you can filter a specific row in the junction table that gets updated (if left out, all corresponding rows get updated).
Hope this helps!
I made the function below for getting usernames from ids. It is not working well.
I can write console.log(result.first_name); within the query function, and the usernames shows up in my terminal, but not the browser. I tried adding “return 'something';” at the end of the function, to see if that showed up in the browser – It did. How can I write the function so that the query result is returned?
function (global function in app.js)
function usernameFromId(id, callback){
db.users.findOne({ _id: ObjectId(id.toString()) }, function(err, result) {
var first_name = result.first_name;
console.log(first_name); // names show up in the console…
callback(first_name);
});
};
page handler (in app.js)
app.get('/books', function(req, res){
function timeSince(dato){
moment.lang('nb');
return moment(dato).fromNow();
};
db.books.find().sort({ added:-1 }, function(err, docs) {
var books = docs;
db.activity.find().limit(9).sort({ time:-1 }, function(err, docs) {
var activity = docs;
res.render('books', {
books: books,
activity: activity,
timeSince: timeSince,
usernameFromId: usernameFromId
})
});
});
});
template (books.jade)
- each a in activity
p=usernameFromId(a.user_id, function(name){return name;})
No because of the asynchronous nature of JavaScript. I have added some comments to your code to indicate the actual order of execution. This is why you are getting the error.
function usernameFromId(id){
var id = id.toString(); // 1
db.users.findOne({ _id: ObjectId(id) }, function(err, result) {
var first_name = result.first_name; // 3
});
return first_name; // 2
};
Edit: you probably want something like the following
function usernameFromId(id, callback){
var id = id.toString();
db.users.findOne({ _id: ObjectId(id) }, function(err, result) {
var first_name = result.first_name;
callback(first_name);
});
};
Okay, I found a solution. Not sure whether it’s any good, but it works. No need for a function.
page handler (in app.js):
app.get('/books', function(req, res){
db.activity.find().limit(9).sort({ time:-1 }, function(err, docs) {
var activity = docs;
db.users.find(function(err, docs) {
var users = docs;
res.render('books', {
page_title:'books',
activity: activity,
users: users
})
});
});
});
template (books.jade):
- each a in activity
- for u in users
- if (a.user_id == u._id.toString())
| #{u.first_name}