Using node.js (v0.10.12) and sequelize (2.0.0-dev9), I am wanting to update attributes within an existing database table. From anther SO discussion I am able to update only one record at a time. I encapsulated the call in a for loop but that updated the same record throughout the for loop.
Could someone help me modify this code to update all records that match the search requirements? Below is my code:
global.db.Task.find({ where: {"Cd": "match"} && {"Desc": null}
}).on('success', function(task) {
if (task) { // if the record exists in the db
task.updateAttributes({
Desc: "New Upate"
}).success(function() {});
}
})
According to the docs you need to do a BulkCreate: (Not tested)
global.db.Task.update(
{Desc: 'New Upate'}, //set attribute
{cd: 'match', Desc: null} //where criteria
).success(function(affectedRows) { ... });
Related
I think I've done enough research on this subject and I've only got a headache.
Here is what I have done and understood: I have restructured my MySQL database so that I will keep my user's data in different tables, I am using foreign keys. Until now I only concluded that foreign keys are only used for consistency and control and they do not automatize or do anything else (for example, to insert data about the same user in two tables I need to use two separate insert statements and the foreign key will not help to make this different or automatic in some way).
Fine. Here is what I want to do: I want to use Sequelize to insert, update and retrieve data altogether from all the related tables at once and I have absolutely no idea on how to do that. For example, if a user registers, I want to be able to insert the data in the table "A" containing some user information and in the same task insert in the table B some other data (like the user's settings in the dedicated table or whatever). Same with retrievals, I want to be able to get an object (or array) with all the related data from different tables fitting in the criteria I want to find by.
Sequelize documentation covers the things in a way that every thing depends on the previous one, and Sequelize is pretty bloated with a lot of stuff I do not need. I do not want to use .sync(). I do not want to use migrations. I have the structure of my database created already and I want Sequelize to attach to it.
Is it possible insert and retrieve several rows related at the same time and getting / using a single Sequelize command / object? How?
Again, by "related data" I mean data "linked" by sharing the same foreign key.
Is it possible insert and retrieve several rows related at the same
time and getting / using a single Sequelize command / object? How?
Yes. What you need is eager loading.
Look at the following example
const User = sequelize.define('user', {
username: Sequelize.STRING,
});
const Address = sequelize.define('add', {
address: Sequelize.STRING,
});
const Designation = sequelize.define('designation', {
designation: Sequelize.STRING,
});
User.hasOne(Address);
User.hasMany(Designation);
sequelize.sync({ force: true })
.then(() => User.create({
username: 'test123',
add: {
address: 'this is dummy address'
},
designations: [
{ designation: 'designation1' },
{ designation: 'designation2' },
],
}, { include: [Address, Designation] }))
.then(user => {
User.findAll({
include: [Address, Designation],
}).then((result) => {
console.log(result);
});
});
In console.log, you will get all the data with all its associated models that you want to include in the query
I have the following scenario, my application has two entities: box and items with N to N relationship. I am using sequelize with MySQL.
I am using pseudocode to represent the tables:
Box {
id: Integer primary key
name: String
}
Item {
id: Integer primary key
name: String
}
I have set up the schemas with relations hasMany in both directions using the following through relation:
Box.hasMany(Item, { through: Box_Item });
Item.hasMany(Box, { through: Box_Item });
Box_Item {
id_box: Integer,
id_item: Integer,
item_order: Integer
}
With primary_key(id_box, id_item).
I tested it and I can call myBox.getItems() on my instance object myBox and easily get all the items it has.
I can make calls as
BoxModel.findOne({
where: { id: 1 },
include: [{ model: ItemModel }]
});
And it automatically understands there is a relation between the models through Box_Item and get everything correctly, except that I'm not getting the results sorted by item_order field. This field is a number from 1 to N that represents the item order inside that box.
I tried
BoxModel.findOne({
where: { id: 1 },
include: [
{
model: ItemModel,
order: 'item_order'
}
]
});
But it seems sequelizejs does not support order inside include yet (checked on their github repo).
I tried to force
BoxModel.findOne({
where: { id: 1 },
order: '`box_model`.`item_order`'
include: [ { model: ItemModel } ]
})
looking through the query sequelize creates but it just put the ORDER BY in two different places (inside INNER JOIN and at the end of the query, don't know why...) and I got an error.
So I searched for this on stackoverflow (1), found a few questions but I don't get a good way for doing that using the ORM.
How could I get the items sorted by item_order field when asking for specific box items?
After a few days trying to get it done I found an answer on stackoverflow that helped me.
After creating the relationships between Box and Item I can easily call on an instance:
myBox.getItems({
order: '`box_model`.`item_order`'
});
And then I get the result I'm expecting. But I had to look through the query sequelize is creating based on the models and get the correct field based on their renaming rules.
If you want you can pass the as parameter and rename your tables.
I have a query I'm trying to perform based on a one to many relationship.
As an example there is a model called Users and one called Projects.
Users hasMany Projects
Projects have many types which are stored in a type (enum) column. There are 4 different types that potentially a user may have that I want to load. The catch is I want to include the most recent project record (createdAt column) for all networks that potentially will be there. I have not found a way to structure the query for it to work as an include. I have however found a way to do a raw query which does what I want.
I am looking for a way without having to do a raw query. By doing the raw query I have to map the returned results to users I've returned from the other method, or I have to do a simple include and then trim off all the results that are not the most recent. The latter is fine, but I see this getting slower as a user will have many projects and it will keep growing steadily.
This allow serialize a json for anywhere action about a model. Read it, very well
sequelize-virtual-fields
// define models
var Person = sequelize.define('Person', { name: Sequelize.STRING });
var Task = sequelize.define('Task', {
name: Sequelize.STRING,
nameWithPerson: {
type: Sequelize.VIRTUAL,
get: function() { return this.name + ' (' + this.Person.name + ')' }
attributes: [ 'name' ],
include: [ { model: Person, attributes: [ 'name' ] } ],
order: [ ['name'], [ Person, 'name' ] ]
}
});
// define associations
Task.belongsTo(Person);
Person.hasMany(Task);
// activate virtual fields functionality
sequelize.initVirtualFields();
Please share your experience with partial updating of JSON document.At now I'm storing my JSON documents in MongoDB which looks like the following:
{
id: ObjectId(507f191e810c19729de860ea),
title: 'Sterling Archer',
comments: [
{text: 'Comment text', tags: ['tag1', 'tag2', 'tag3']},
{text: 'Comment test', tags: ['tag2', 'tag5']}
]
}
I need to frequently update my documents by using rfc6902 specification. Now, I do it not optimized way that looks the following (I use nodejs/express/mongoose and fast-json-patch module in this example):
var jsonpatch = require('fast-json-patch');
app.patch('/document/:id', function (req, res, next) {
var document_id = req.params.id;
// req.body.patch: { "op": "add", "path": "/comments/2", "value": {text: 'Comment test3', tags: ['tag4']}" }
var patches = req.body.patch;
// find document
Document.findById(document_id, function (err, document) {
// Applying patches
jsonpatch.apply(document, patches);
// Update whole document in MongoDB
Document.update({_id: document_id}, document, function (err) {
return res.status(200).send();
});
});
});
This is not optimize approach to patch documents due two queries in MongoDB and replacing whole document. So I'm looking for optimized approach and want to try RethinkDB for this task. Can you help me to inspect possibility of atomic document updating by using single query with RethinkDB? Or should I looks for another way of resolving my problem?
Please share your experience with partial updating of JSON document.
You just need one query in RethinkDB. Suppose you want to update the document whose id is 1 with the values {foo: 1, bar: 2}, and increment the field "count", you would do
r.table("data").get(1).update(function(doc) {
return doc.merge({foo: 1, bar:2, count: doc("count").add(1) })
})
While this update requires a unique query, the whole document will be updated.
If you have big documents, you can split them in multiple tables and perform joins later to retrieve the data.
You may be interested in reading this article about data modeling: http://www.rethinkdb.com/docs/data-modeling/
Alright so I have a project in NodeJS where I'm utilizing Sequelize for a MySQL ORM. The thing works fantastically however I'm trying to figure out if there is a way to specify what fields are being returned on a query basis or if there's even a way just to do a .query() somewhere.
For example in our user database there can be ridiculous amounts of records and columns. In this case I need to return three columns only so it would be faster to get just those columns. However, Sequelize just queries the table for everything "*" to fulfill the full object model as much as possible. This is the functionality I'd like to bypass in this particular area of the application.
You have to specify the attributes as a property in the object that you pass to findAll():
Project.findAll({attributes: ['name', 'age']}).on('success', function (projects) {
console.log(projects);
});
How I found this:
The query is first called here: https://github.com/sdepold/sequelize/blob/master/lib/model-definition.js#L131
Then gets constructed here: https://github.com/sdepold/sequelize/blob/master/lib/connectors/mysql/query-generator.js#L56-59
Try this in new version
template.findAll({
where: {
user_id: req.params.user_id
},
attributes: ['id', 'template_name'],
}).then(function (list) {
res.status(200).json(list);
})
Use the arrays in the attribute key. You can do nested arrays for aliases.
Project.findAll({
attributes: ['id', ['name', 'project_name']],
where: {id: req.params.id}
})
.then(function(projects) {
res.json(projects);
})
Will yield:
SELECT id, name AS project_name FROM projects WHERE id = ...;
All Answers are correct but we can also use include and exclude as well
Model.findAll({
attributes: { include: ['id'] }
});
Model.findAll({
attributes: { exclude: ['createdAt'] }
});
Source