I have a database like this.
+----------------+
| Tables_in_test |
+----------------+
| a_b |
| a_c |
| as |
| bs |
| cs |
+----------------+
bs and cs tables have many to many relationship with as table. So a_b table and a_c table are pivot tables.
This is as table
+----+------+
| id | name |
+----+------+
| 1 | A1 |
| 2 | A2 |
+----+------+
This is bs table
+----+------+
| id | name |
+----+------+
| 1 | B1 |
+----+------+
And this is cs table
+----+------+------+
| id | b_id | name |
+----+------+------+
| 1 | 1 | C1 |
| 2 | 1 | C2 |
+----+------+------+
this is a_b pivot table
+------+------+
| a_id | b_id |
+------+------+
| 1 | 1 |
+------+------+
And this is a_c pivot table.
+------+------+
| a_id | c_id |
+------+------+
| 1 | 1 |
| 2 | 2 |
+------+------+
And this is my A model for the as table.
class A extends Model
{
protected $table = "as";
public function b(){
return $this->belongsToMany("App\B");
}
public function c(){
return $this->belongsToMany("App\C");
}
}
And this is B model for bs table
class B extends Model
{
protected $table = "bs";
public function c(){
return $this->hasMany("App\C");
}
}
I just want to query C table values as related to A table.
I tried this query
A::where("id",1)->with("b.c")->get();
But this result also gives me C2 value which is related to A2 in "as" table. I want to get only C1 value which is related only A1 value in "as" table.
How can I do this ? Thank you for your help
In your example data A1 relates to B1 which in turn relates to C2. And you are in fact nesting the b.c eager load, so you are loading Bs and Cs related to those Bs.
Have you tried A::where("id",1)->with(["b", "c"])->get();
?
Related
Suppose we have 3 entities named A, B, and C. And Relations between these Entities are something like this:
A -- one to many --> B
B -- many to many --> C
Example tables:
A
| id |
| -- |
| 1 |
| 2 |
B
| id | a_id |
| -- | -- |
| 1 | 1 |
| 2 | 2 |
B_C
| b_id | c_id |
| -- | -- |
| 1 | 1 |
| 2 | 2 |
C
| id |
| -- |
| 1 |
| 2 |
If we wanna make the relationship between A and C in laravel, what should we do? is it possible at all?
For these situations, you can use Has Many Through relationships and for more information, you can follow the laravel documentation.
to get the relation between your A and C model you can use has many though like this:
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class A extends Model
{
public function c()
{
return $this->hasManyThrough(
C::class,
B::class,
'a_id', // Foreign key on the a table...
'b_id', // Foreign key on the b table...
'id', // Local key on the a table...
'id' // Local key on the b table...);
}
}
The first argument passed to the hasManyThrough method is the name of the final model we wish to access, while the second argument is the name of the intermediate model.
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);
How can I sort the products in table1 according to their connection with table2 i.e. sort the products in table1 by example_relation in table2?
Table1
| id | product |
|----|---------|
| 1 | pro1 |
| 2 | pro2 |
| 3 | pro3 |
| 4 | pro4 |
| 5 | pro5 |
Table2
| id | example_relation | product_id |
|----|------------------|------------|
| 1 | 700 | 1 |
| 2 | 800 | 2 |
| 3 | 900 | 3 |
| 4 | 850 | 2 |
| 5 | 600 | 4 |
| 6 | 125 | 5 |
Table1 model page:
public $belongsTo = [
'pro_relation' => [
'models\Model',
'key' => 'id',
'otherKey' => 'product_id',
],
Sorting section that needs to be arranged correctly:
$query->whereHas('pro_relation', function($q) use ($postFrom,$postTo){
$q->select('example_relation END AS expose');
})->orderBy("expose", DESC);
Okay, when you want to order the result of one table from another table then you can use orderBy() inside a closure of the relationship to another table.
So from your query, you can add orderBy() like so.
$query->whereHas('pro_relation', function($q) use ($postFrom,$postTo){
$q->select('example_relation END AS expose')
->orderBy('example_relation');
});
This is work
$query->join('table2', 'table1.id', '=', 'table2.yacht_id')
->orderBy(example_relation DESC);
How do I store data in users.sport_id:
User class:
public function sport() {
return $this->belongsToMany('App\Sport');
}
Where sports table has:
+----+------------+
| id | sport |
+----+------------+
| 1 | baseball |
+----+------------+
| 2 | basketball |
+----+------------+
Do I add to user.sport_id = 1,2 or save it as array [1,2] and use $casts = ['sport_id'=>'array'];
User table
id | name | user_type | email | password
1 | John | 1 | john#gmail.com | something
2 | Roy | 1 | roy#gmail.com | something
3 | Rax | 1 | Rax#gmail.com | something
4 | Ren | 1 | ren#gmail.com | something
AssignUser Table
id | user_id | assign_to_math | assign_to_chemistry
1 | 3 | 2 | 1
2 | 4 | 1 | 2
So, here is users table where four users are avail
Now in assign table first row Rax is assign tuitoin for math to Roy and chemistry to John
I want to get the detail of john and roy with relation
I tried in User models
public function getInfoFormathTutor(){
return $this->hasOne('App\AssignUser', 'id', 'assign_to_math');
}
It return for me null value don't know why please help
Thanks in advance
try:
public function getInfoFormathTutor(){
return $this->hasOne('App\AssignUser', 'assign_to_math', 'id');
}