I have an order and transaction model in which 1 order can have many transactions.
However, there are certain areas in which I will only want to return certain rows of the transactions table.
I did something like this:
Order::with('transactions')->whereHas('transactions',function($query){
$query->select(array('A','B'));
}))
Where A and B are the columns of the transactions.
How do I get this to work without changing the name of the relationship?
Related
new to laravel.
My use case:
Update multiple rows (say: resources table).
Create multiple users (users table).
Retrieve ids of created users
What I currently did:
First, Update the resources table whereIn('id', [1,2,3,4]). (Update eloquent)
Second, Get array of the updated resources (Another eloquent: Resource::whereIn('id', [1,2,3,4])->get()->toArray())
Bulk create a users. Refers to the resources collection above. (Another eloquent: User::create($resources))
Lastly, get the ids of the created users (Not resolved yet. But I might have to use another eloquent query)
All in all, there are 4 Eloquent queries, which I want to avoid, because this might have performance issue.
What I wanted to do is that, On first step(Update), I should be able to get a collection of models of the affected rows (But I can't find any reference on how to achieve this). And then use this collection to create the users, and get the users ids in one query with User::create() so that I will have 2 queries in total.
There is no need to invent performance problems that do not exist.
Update or Insert return only count of affected rows. Commands Select, Insert, Update performed separately. This is a SQL issue, not Laravel.
For single inserts (if you want add one row) you can use insertGetId method of a model.
For example,
$id = User::insertGetId([
'email' => 'john#example.com',
'name' => 'john'
]);
But you get only ID of record. You need to run select to get full data of the row.
To save multiple records with one query you can use
DB::table('table_name')->insert($data);
Since this won't be an eloquent method, you should pass all the columns including created_at and updated_at.
I don't know what is the method name for update.
Using Eloquent, I'm trying to make a polymorphic relationship between some models that isn't working out. Simplified, it works like this: there is a model 'groups', which obviously can contain some groups. Now each of these groups can either contain 'members' or 'guests', so I have a table and model for both of them. These are not similar to each other. My groups table contains a column in which model to use (members or guests). The structure is as follows:
groups (\App\Models\Group)
id
name
model (either \App\Models\Member or \App\Models\Guest)
members (\App\Models\Member)
id
group_id
first_name
last_name
address
email
.....
guests (\App\Models\Guest)
id
group_id
name
So the relationship 'people' in a group retrieves either the members or the guests. Using the default $this->morphTo() function using the group_id is able to retrieve the correct results, but due to its logic only returns one result, while I need all results. The rest of the app is indifferent to whether the people are members or guests, so I do not want to split those two up here.
Any ideas on how to accomplish this? I'm trying to eager load the relationship.
CONTEXT:
I want to monitor payment transactions for money laundering, where payments cross multiple borders. There are a max of 6 countries shown per transaction. For each of these countries, I need to know a risk level.
I have 2 tables:
Transaction data (where there are many transactions from same country)
Country Risk (containing each country once, with an added risk classification. There are 100+ countries, and only 6 different Risk levels).
Problem:
I would like to look up the Risk Classification per country in Transaction Data. The problem is, there are 6 countries per transaction in Transaction Data. So I have to link Transaction data to Country Risk 6 times. Only 1 relationship can be active, of course.
So I tried writing the following measure:
CALCULATE(
VALUES('Country Risk'[Risk classification]);
USERELATIONSHIP('Transaction Data'[Country 2];'Country Risk'[Country Code]))
I get an error though when using the measure in a graph where I listed the countries from Transaction Data (where every country is mentioned in multiple rows) and I wanted to see the related risk categories:
A table of multiple values was supplied where a single value was expected
What am I doing wrong?
Made similar test data: https://drive.google.com/file/d/1_kJW-BpbrwCsbSpxdo7AJ3IzPy2oLWFJ/view?usp=sharing
Needed:
for every C (C1-C6) column I need to add the risk category.
For every C column I need to make a pie chart showing the number of transactions per risk category for that C column
Pie charts should filter the transaction oevrview: (
I've taked a PBI consultant about this, there is no way to get this issue solved the way I want it to (to have multiple relationships between 2 tables all acting as if they were active relationships at same time).
the only way of getting it done would be:
1. write measures (but that doesn't allow cross filtering between pie chart and table below)
2. unpivot the country columns (but that wouldn't allow to have 6 columns with risk category in table)
3. have 6 dimension tables (this solves the issue, because it allows both cross filtering between piechart and other piecharts & table. and it would allow to have 6 columns for separate risks in the table visual)
thanks for trying to help guys!
I've just started using Laravel and I'm coming from a different system using an existing database. In this system there are 2 users table, one stock with the CMS and one custom one.
I want to create an Eloquent model which retrieves data from both tables into one model. I know I can use the following to create a relationship.
$this->hasOne('App\SecondUser', 'id', 'id);
But this results in 2 sql queries, and I want to join results from 2 tables before returning the model, in one join statement. How do I do this?
That might be a bit more complicated that you would expect.
First of all you have to use \DB facade to join the two collections(arrays) and then recreate the Eloquent collection from these arrays using Collection's make method.
More info about the Collection class here
An easier way might be to join them using standard laravel relationships and user something like Model::user->with('relation')->get.
But this will still create 2 queries (still relatively fast).
I notice that in hibernate, it queries the child collections of entities an entity at a time. So, for example, I have a Person entity with a OneToMany relationship with PhoneNumber as well as a OneToMany relationship with EmailAddress. If I do a simple query on the Person entity that returns 1,000 people then hibernate will make 1,000 queries to EmailAddress and 1,000 queries to PhoneNumber. Let's forget about eager or lazy fetching for a minute and assume I will be accessing the phone and email collections of every person.
This seems like a naive implementation. Is there a simple way to change this so there is only 1 query into PhoneNumber and only 1 query into EmailAddress? These should be put into a map keyed by their Person foreign key so they are easily retrieved by the Person getter methods.
Any thoughts besides doing a brute force query into the session cache for emails and phone numbers BEFORE executing the Person query?
TIA, let me know if you need additional data.
Apart for doing the queries by yourself, you could simply enable batch fetching, as described in the documentation:
You can also enable batch fetching of collections. For example, if each Person has a lazy collection of Cats, and 10 persons are currently loaded in the Session, iterating through all persons will generate 10 SELECTs, one for every call to getCats(). If you enable batch fetching for the cats collection in the mapping of Person, Hibernate can pre-fetch collections: