I have two collection types in Strapi, created with many-to-many relation.
What is the proper way to write a custom query to update only the relation?
**user**
id name
1 user1
**store**
id name
1 store1
**user_saved_stores__stores_saved_users**
id user_id store_id
1 1 1
I can use the default PUT API to update the relation like this, but I would need to find out every single user before calling the API, as it would overwrite all the many-to-many relations.
const xhr = new XMLHttpRequest();
xhr.open('PUT', '/stores/1', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
JSON.stringify({
savedUser: ["1","2"],
})
);
If I would like to add or remove only one user to the relations, what should be the best way without writing custom SQL query?
Currently seems not any straight forward support in strapi for many to many relationships update. So either writing custom queries inside the above PUT api , of create separate api directly to update the ** user_saved_stores__stores_saved_users** table created by strapi
Related
Model - User
id [999]
name [foo]
Model - Post (without User Foreign Key)
id [1]
unique_key [USR_00000999]
data [bar]
I would like to get all user with related posts (one to many) by using "custom key" value, is this possible with build in eloquent?
I only manage to looping using foreach one by one with
Post::query()
->where('unique_key', sprintf('USR_%08d', $user_id))
->count();
That is not built-into Laravel by default... if you want to know why it's because it's not a common thing that everyone does...
BUT, you can use scope query so you don't need to do the sprintf everytime...
Laravel Query Scopes Documentation
But I want to ask, why wouldn't you just add user_id on your post table and just have an Accessors on your post model for generating the unique_key? That would be much easier on my perspective...
Laravel Accessor Documentation
UPDATE: (See Comment)
Is it possible to have an empty user_id on Posts table?
then populate it when the user is created?
say you have a posts with key of USR_00000999... and you have a user with an id of 999... when you create that user you'll just have to update all posts with key of USR_00000999 to have a user_id of 999...
golang gorm allows us to retrive (or) update records without creating models and using map[string]interface{}{}. But how to create a record without using a model ?
I have created two content type builder which are category and sub-category respectively. While adding sub-category I had define one relationship which is one-to-many.
After creating successfully, I found that the basic CRUD API has been created and it works fine.
Now I need to find data like if I pass category-id then it has to return me it's all sub-category list.
Well, for this I can also write API manually, But I thought that strapi provides a feature of relationship though it may have some way to fetch data from the relationship table. In my app, I had set up a project with MySQL.
Expected output: Need a way to fetch data from a relation without writing custom API. Looking for inbuilt feature of strapi.
You have to use deep filtering.
📚Here is the documentation https://strapi.io/documentation/3.0.0-beta.x/guides/filters.html#deep-filtering
So you will be able to do /categories?sub-category.id=[your id]
Laravel Version: 5.5
PHP Version: 7+
Database Driver & Version: mysql 5.7+
Scenario:
I have a SaaS application that has flexible database structure, so its fields are bound to change, especially given it has a Json field (for any extra database structure to be created from client side of the application), including relationship based fields. so Account Table can have dynamically created employee_id field, and thus the need to access relationships dynamically
Problem:
I need to EagerLoad models based on this dynamic relationship. If I had something like this:
// Account Model
public function employee(){
return $this->belongsTo(App\Employee);
}
it would be easy. But what I have is this:
public function modelBelongsTo(){
return $this->belongsTo($dynamicClassName, $dynamicForeignKey);
}
Now if I eager load this, I'll get Account Model instance with related Employee on key modelBelongsTo. This is how Eloquent Names based on the function of eagerload. But after this I cannot use this function again to eagerload a second model because it'll just overwrite results on modelBelongsTo key.
Possible Solution Directions:
1) Can I Somehow change laravel's process to use a name I provide?
or
2) Can I write functions on the fly to overcome this so I'll write employee function on the fly?
or
3) Worst Case Scenario: I iterate over all records to rename their keys individually because I am using a pagination, it wouldn't that big of a deal to loop over 10 records.
Us a morph relationship
define the various dynamic classnames say
Employee
Boss
Morph works by having the related key and the table name stored in the parent table, it means to relate them you have to use a join or an orm and you cant have foreign key constraint on it as it links to different tables.
then have your account have morphs where
we have
Account
as top class
then we have
EmployeeAccount, BossAccount
which have their relation to boss and employee
then in Account have morphto relation call it specificAccount()
to which in its child morphs have the morph relation to Account
then add it to $with so to eager load them so when fetching account you could simply do
$account ->specificAccount
to get its morph child. which is nullable
This is totally dynamic such that if you have other classes in future you can just add and add the morph relationship. This may be applied to any reflection or runtime evaluated and loaded classes/code though it is not advisable to do this, as you can always edit code to create new functionality without affecting previous.
I have two tables, in which one user can have several contacts:
User(UserId, UserName)
Contact(UserId, ContactId)
Suppose I would like to get all the ContactNames from the UserNames in the User Table by the Userid.
Note that the Contact table cannot be seen in the current data context, it has been turned into a many to many relationship
How can I do the query？
What If I need to insert or delete?
I tried the "include" method but it does not work. Do you have any suggestions?
Thank you very much.
var id = 1; // id to find
context.Users
.Where(x=>x.UserId = id)
.SelectMany(x=>x.Users)
.Select(x=>x.UserName)
.ToArray();
After generation from db your model has 2 sub-collections: Users and Users1.
One of it corresponds to users, that are contacts for current user.
Another stores users, that current user is contact for.
You can rename them to represent their meaning to Contacts and ContactsFor via editor.
If you still want to have 2 types instead of Type+(Many-To-Many Ref), then in editor you can delete reference, create new entity Contact, setup all mapping, add references. After all this is done - you will have model look like this:
To Achieve this:
Delete Many-To-Many reference
Crete new Entity Contact
Add properties ContactId and UserId, set StoreGeneratedPattern to none
Add mappings for Contact
Add associations for Contacts and ContactFor
But it's not that easy.