How to make a deep relationship with eloquent? I'm trying to display the data like this :
+------------------------------------+
| Main ID | Name | SN | Last Event |
|------------------------------------|
| 12 | James | j89 | RIGHT |
+------------------------------------+
The "Last Event" column is based on the latest data on "Tracks" table but the value "RIGHT" is relation between the "Tracks" table with "Events" table. So, in this table, the latest record in the tracks table is id of 9 with event_id of 12, the event_id of 12 in the Events table has name column that contained value RIGHT. That value that I want to grab it to display in front end. this is my table in database.
Main table
+---------------+
|id | name | sn |
|---------------|
|12 | James| j89|
+---------------+
Tracks table
+-------------------------------------+
|id | main_id | event_id | created_at |
|-------------------------------------|
| 5 | 10 | 10 | 2021-10-12 |
| 9 | 10 | 12 | 2021-11-20 |
+-------------------------------------+
Events
+----------+
|id | name |
|----------|
|10 | LEFT |
|12 | RIGHT|
+----------+
If I use has one relationship with latestOfMany() method, it didn't reach to the events table. How do I reach it to the Events table to grab the value in Events table through the latest data of Tracks table based on main_id? thanks!
you can use Eager Loading to load deep in your relation, if you setup your relation correctly:
class Main extends Model
{
public function latestTrack()
{
return $this->hasOne(Track::class,'main_id')->latestOfMany();
}
}
class Track extends Model
{
public function event()
{
return $this->belongsTo(Event::class,'event_id');
}
}
now you can get the structre you need:
$main=Main::with('latestTrack.event:id,name')->find(12);
Related
I am trying to build a Survey Module in Laravel where user can create survey, assign questions and options to the questions in survey.
survey can have multiple questions
survey question can have multiple options
To meet the above requirement I created the following models & tables
Model: Question
Table: questions
| id | question |
| -------- | -------------------------|
| 1 | How is the performance? |
| 2 | How did you know about us|
Model: Option
Table: options
| id | option |
| --- | --------- |
| 1 | Good |
| 2 | Bad |
| 3 | Google |
| 2 | SMS |
Now the relationship between questions and survey will be stored in pivot table
Model: SurveyQuestion
Table: survey_questions
| id | survey_id| question_id |
| ---| -------- |-------------|
| 1 | 1 |1 |
| 1 | 1 |2 |
Upto this point I know how to store data into pivot table using attach/sync.
Now the problem is As per requirement each survey question might have multiple options so I created another pivot table survey_question_option in which I am using survey_questions primary key as foreign key.
Model: SurveyQuestionOption
Table: survey_question_options
| id | survey_question_id| option_id |
| -- | ----------------- |-----------|
| 1 | 1 |1 |
| 1 | 1 |2 |
Now my question is that is it correct to use pivot table primary key as foreign key into another table?
If yes then how can I store data into survey_question_options table using laravel relationships?
If no then what is the better solution?
In this case you can create a Custom Intermediate Table Model (Custom Pivot)
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Relations\Pivot;
class SurveyQuestion extends Pivot
{
public function options()
{
//You need to create a pivot pivot table survey_question_option
//with (survey_question_id, option_id)
return $this->belongsToMany(Option::class, 'survey_question_option');
}
}
Your models will need to recognize this new Pivot Model with the method using(). Here is an example with Survey Model
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Survey extends Model
{
/**
* The users that belong to the role.
*/
public function questions()
{
return $this
->belongsToMany(Question::class)
->using(SurveyQuestion::class);
}
}
And them you will be able to access via eloquent like this
$survey->questions->pivot->options
For more information you can check the documentation here:
https://laravel.com/docs/8.x/eloquent-relationships#defining-custom-intermediate-table-models
I am trying to join two columns with a table.
Here is my table structure for tasks table
| id | assigned_by | assigned_to |
| :--- | :---: | ---: |
| 1 | 1 | 2 |
| 2 | 1 | 3 |
Here is the table structure of users table.
| id | name | email |
| :--- | :---: | ---: |
| 1 |varun | me#gmail.com |
| 2 |mark | mark#gmail.com|
I tried below code in Task Class it didn't work
public function user()
{
return $this->belongsTo(User::class);
}
Eloquent will automatically determine the proper foreign key column on the User model. By convention, Eloquent will take the "snake case" name of the owning model and suffix it with _id. So, for your example, Eloquent will assume the foreign key on the User model is user_id.
However, your foreign_key is assigned_by and assigned_to, so you need to specify the foreign_key:
public function assignedUser()
{
return $this->belongsTo(User::class, 'assigned_to');
}
public function assignedByUser()
{
return $this->belongsTo(User::class, 'assigned_by');
}
I am trying to retrieve database rows with their relationships. However, the local key is an array. Let me explain using an example.
Lets say I have a table of countries and a table of pages. Each country can have many pages. Each page can belong to multiple countries. I do not have the flexibility to change this schema.
pages
+-------------+-----------+
| id | name | countries |
+-------------+-----------+
| 1 | Page 1 | 1 |
+-------------+-----------+
| 2 | Page 2 | 1,2,3 |
+-------------+-----------+
| 3 | Page 3 | 4,5,6 |
+-------------+-----------+
countries
+----+----------------+
| id | name |
+----+----------------+
| 1 | United States |
+----+----------------+
| 2 | United Kingdom |
+----+----------------+
| 3 | Germany |
+----+----------------+
| 4 | France |
+----+----------------+
| 5 | Hong Kong |
+----+----------------+
| 6 | Thailand |
+----+----------------+
| 7 | Belgium |
+----+----------------+
| 8 | Singapore |
+----+----------------+
My model and controller look something like:
country
public function pages()
{
return $this->hasMany(Page::class, 'id', 'countries');
}
MemberController.php
$countries = Country::with('pages')->get();
This is returning all countries, but only Page 1 contains any relationships.
Is there a way to retrieve relationships using a whereIn approach so all three countries will return appropriate pages?
Thanks in advance
Since Page can belong to many Countries, you need to create a pivot table called country_page and remove the countries column.
Then define two belongsToMany() relationships in both models:
public function pages()
{
return $this->belongsToMany(Page::class);
}
If you're not following Laravel naming conventions listed in my repo and you gave the pivot name a custom name, define it too:
public function pages()
{
return $this->belongsToMany(Page::class, 'custom_pivot_table');
}
Something like this ?
$datas = Pages::where( ##your conditions### )->get()->inArray();
$countries = Countries::pluck('name','id'); // return array of id=>name
foreach($datas as $key=>$data) {
$c = [];
foreach(explode(',',$data['countries']) as $country_id) {
$c[]=$countries[$country_id];
//or
$c[]= ['id'=>$country_id,'name'=>$countries[$country_id]];
}
$datas[$key]['countries']= $c;
}
I have two simple tables, cats and breeds:
mysql> select * from cats;
+----+--------+---------------+----------+---------------------+---------------------+
| id | name | date_of_birth | breed_id | created_at | updated_at |
+----+--------+---------------+----------+---------------------+---------------------+
| 1 | Rita | 2008-07-06 | 1 | 2015-05-09 20:40:49 | 2015-05-09 20:50:20 |
| 2 | Muni | 1992-05-15 | 3 | 2015-05-09 20:50:54 | 2015-05-09 20:50:54 |
| 3 | Hector | 2005-01-23 | 4 | 2015-05-09 21:08:23 | 2015-05-09 21:08:23 |
+----+--------+---------------+----------+---------------------+---------------------+
3 rows in set (0.00 sec)
mysql> select * from breeds;
+----+------------+
| id | name |
+----+------------+
| 1 | Domestic |
| 2 | Persian |
| 3 | Siamese |
| 4 | Abyssinian |
+----+------------+
4 rows in set (0.00 sec)
All I want to do is get a list of the cats that are of a certain breed. In the cats table, breed_id is a FK that points to the PK of the breeds table. The example code in my book which is supposed to return a view with all cats of a specific breed returns no results:
The url I am trying is /cats/breeds/Domestic
The view that is generated uses this logic in the routes.php file:
Route::get('cats/breeds/{name}', function($name)
{
$cats = Furbook\Cat::with('breeds')
->whereName($name)
->get();
dd($cats);
});
When I dd($cats) I get zero results even though I have a cat with a domestic breed_id of 1. What have I done wrong here?
EDIT:
I can get it to work with the following hacky code, which first gets the id from the breeds table by querying against the name field, then queries the cats table with that id:
$breed = Furbook\Breed::whereName($name)->get();
$id = $breed[0]['attributes']['id'];
$cats = Furbook\Cat::whereId($id)->get();
How do I make this into one Eloquent query? I see no examples for this kind of query on the Laravel site.
For more information this is how the models look:
class Breed extends Model {
public $timestamps = false;
public function cats()
{
return $this->hasMany('Furbook\Breed');
}
}
class Cat extends Model {
protected $fillable = [
'name',
'date_of_birth',
'breed_id',
];
public function breed()
{
return $this->belongsTo('Furbook\Breed');
}
}
You're asking the system to give you all cats with a name of Domestic - not all cats of the breed name Domestic.
Assuming your model relationships are in order, you could do e.g.
$cats = Furbook\Breed::whereName($name)->first()->cats;
Also, my Burmese cat just hit the monitor; I think she's upset that she's not in the breeds list.
In MS Access (2013 if it matters), is it possible to have a calculate field in a table that displays the result of a query on another table?
For example, let's say my tables are (stars indicate primary key) -
Table Customers
*Customer ID | First name | Last name
------------------------------------
1 | John | Doe
2 | Joe | Smith
Table Purchases
*Purchase ID |Customer ID | Product | Last name | Notes
----------------------------------------------------------
25 |1 | Chair | Doe |
45 |1 | Table | Doe |
46 |2 | Table | Smith |
Every time a customer buys something, I add a a new row to Purchases. However, when I type in their Customer ID, I would like Last name to be filled in automatically.