I am trying to find a way to remove rows from the DB through the parent model (menu) that has many children (foods). I only want to delete certain rows though, not all.
Menu.js
...
Menu.hasMany(models.Food, {
as: 'foods',
foreignKey: 'menuId',
sourceKey: 'id'
});
...
In my controller I have the following to try and delete certain foods off the menu.
...
const result = await menu.destroyFoods({
where: {
name: ['Pasta', 'Pizza']
}
});
...
I have also tried singular destroyFood as well. For both I am getting destoryFood/destoryFoods is not a function. Is there any easy way to do this from the instance of menu? New to sequelize, would love some help. Thanks.
Thanks
You can use menu.removeFoods() and menu.removeFood() - see Special methods/mixins added to instances: Foo.hasMany(Bar) for more information.
You will also need to use the Op.in query operator to specify multiple values for Food.name.
const { Op } = require('sequelize');
const result = await menu.removeFoods({
where: {
name: {
[Op.in]: ['Pasta', 'Pizza'],
}
}
});
This is the equivalent of calling Food.destroy() where the menuId is equal to the menu.id from the earlier result.
const results = await Food.destroy({
where: {
menuId: menu.id,
name: {
[Op.in]: ['Pasta', 'Pizza'],
},
},
});
Related
In user schema, Location is an array of objects with locations._id is ObjectId.
This is my user service file.
const updatedBy = {
_id: mongoose.Types.ObjectId(req.params.id),
"locations._id": { $in: req.body.locationIds },
};
const updatingData = { $set: { "locations.$.status": req.query.status }};
const user = await userDbServices.updateRecords(updatedBy, updatingData);
In req.body.locationIds, I'm passing an array.
And this one is the user DB service file
exports.updateRecords = async function (updateParam, updatingData) {
return userModel.updateMany(updateParam, updatingData);
};
When I hit the API, The first embedded document of location is updated. But the other ones aren't. How can I solve this?
This is actually the expected behavior of the $ identifier, from the docs:
the positional $ operator acts as a placeholder for the first element that matches the query document
To update multiple elements you want to be using the $[] identifier with arrayFilters, like so:
userModel.updateMany({
_id: mongoose.Types.ObjectId(req.params.id),
"locations._id": { $in: req.body.locationIds },
},
{
$set: {
"locations.$[elem].status": req.query.status
}
},
{
arrayFilters: [
{
"elem._id": {
$in: req.body.locationIds
}
}
]
})
Mongo Playground
I want to update a subfield(present as object) entry given the id of the parent as well as child object.
const QuestionSchema = mongoose.Schema({ //_id1
...
...
comment: [{ //_id2
commentBody: String,
...
...
}]
}]
Above shown is the schema and I want to update commentBody of a particular field as object "comment" , given <_id1> as id of question and <_id2> as id of comment.
I have tried as a beginner but it is not working.
Please configure the syntactic or logical error in this code.
const updatedQuestioncomment = await Questions.findByIdAndUpdate({ "_id": _id1 }, { "comment._id": id2 }, { $set: { 'comment': [{ 'commentBody': commentBody }] } });
Thank you!!
I believe this is what you want...
const doc = await Questions.findOneAndUpdate(
{'_id': _id1, 'comment._id': id2},
{ '$set': { 'comment.$.commentBody': 'CHANGED!' } }
);
I have got a data structure:
{
field: 1,
field: 3,
field: [
{ _id: xxx , subfield: 1 },
{ _id: xxx , subfield: 1 },
]
}
I need to update a certain element in the array.
So far I can only do that by pulling out old object and pushing in a new one, but it changes the file order.
My implementation:
const product = await ProductModel.findOne({ _id: productID });
const price = product.prices.find( (price: any) => price._id == id );
if(!price) {
throw {
type: 'ProductPriceError',
code: 404,
message: `Coundn't find price with provided ID: ${id}`,
success: false,
}
}
product.prices.pull({ _id: id })
product.prices.push(Object.assign(price, payload))
await product.save()
and I wonder if there is any atomic way to implement that. Because this approach doesn't seem to be secured.
Yes, you can update a particular object in the array if you can find it.
Have a look at the positional '$' operator here.
Your current implementation using mongoose will then be somewhat like this:
await ProductModel.updateOne(
{ _id: productID, 'prices._id': id },//Finding Product with the particular price
{ $set: { 'prices.$.subField': subFieldValue } },
);
Notice the '$' symbol in prices.$.subField. MongoDB is smart enough to only update the element at the index which was found by the query.
I'm trying to delete a mongodb object and then once deleted, I want to delete everything associated with that mongodb object. Including nested mongodb objects from my mongo database.
var parentObjectSchema = new mongoose.Schema({
name: String,
split: Number,
parts: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "ChildObjectSchema"
}
],
});
var childObjectSchema = new mongoose.Schema({
name: String,
number: Number,
things: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Things"
}
],
});
So I am trying to delete the parentObject, and childObjects that come along with it. Not sure how I would go about doing that. I am successful in deleting the parentObject but that childObject is still in the mongodb, taking up space. Any ideas?
MongoDB doesn't provide the notion of foreign keys like other databases do. Mongoose has convenience methods in the client library that populates your documents with other documents using multiple queries and joining the results:
https://mongoosejs.com/docs/populate.html
If you want to do a cascading deletion then you'll need to grab the object ids of the children in the parent documents you want to delete, and then execute a delete against those children documents.
Here's a simplified example:
const deleteThing = (thingId) => {
thingObjectSchema.remove({ _id: thingId });
};
const deleteChild = (childId) => {
childObjectSchema.findOne({ _id: childId }).select('things').lean().exec((err, child) => {
for (const thingId of child.things) {
deleteThing(thingId);
}
childObjectSchema.remove({ _id: childId });
})
};
const deleteParent = (parentId) => {
parentObjectSchema.findOne({ _id: parentId }).select('parts').lean().exec((err, parent) => {
for (const childId of parent.parts) {
deleteChild(childId);
}
parentObjectSchema.remove({ _id: parentId });
})
};
// note: not actually tested
I'm using normalizr util to process API response based on non-ids model. As I know, typically normalizr works with ids model, but maybe there is a some way to generate ids "on the go"?
My API response example:
```
// input data:
const inputData = {
doctors: [
{
name: Jon,
post: chief
},
{
name: Marta,
post: nurse
},
//....
}
// expected output data:
const outputData = {
entities: {
nameCards : {
uniqueID_0: { id: uniqueID_0, name: Jon, post: uniqueID_3 },
uniqueID_1: { id: uniqueID_1, name: Marta, post: uniqueID_4 }
},
positions: {
uniqueID_3: { id: uniqueID_3, post: chief },
uniqueID_4: { id: uniqueID_4, post: nurse }
}
},
result: uniqueID_0
}
```
P.S.
I heard from someone about generating IDs "by the hood" in normalizr for such cases as my, but I did found such solution.
As mentioned in this issue:
Normalizr is never going to be able to generate unique IDs for you. We
don't do any memoization or anything internally, as that would be
unnecessary for most people.
Your working solution is okay, but will fail if you receive one of
these entities again later from another API endpoint.
My recommendation would be to find something that's constant and
unique on your entities and use that as something to generate unique
IDs from.
And then, as mentioned in the docs, you need to set idAttribute to replace 'id' with another key:
const data = { id_str: '123', url: 'https://twitter.com', user: { id_str: '456', name: 'Jimmy' } };
const user = new schema.Entity('users', {}, { idAttribute: 'id_str' });
const tweet = new schema.Entity('tweets', { user: user }, {
idAttribute: 'id_str',
// Apply everything from entityB over entityA, except for "favorites"
mergeStrategy: (entityA, entityB) => ({
...entityA,
...entityB,
favorites: entityA.favorites
}),
// Remove the URL field from the entity
processStrategy: (entity) => omit(entity, 'url')
});
const normalizedData = normalize(data, tweet);
EDIT
You can always provide unique id's using external lib or by hand:
inputData.doctors = inputData.doctors.map((doc, idx) => ({
...doc,
id: `doctor_${idx}`
}))
Have a processStrategy which is basically a function and in that function assign your id's there, ie. value.id = uuid(). Visit the link below to see an example https://github.com/paularmstrong/normalizr/issues/256