My target is to get collection of books with count of matches book.names in another table without relation
I get collection like this
$books = Books::paginate(20);
What I need now is to get the count of matches like this
SELECT COUNT(*) FROM `posts` WHERE `body` LIKE '%book.name%'
How can I do this with one query and avoiding unnecessary queries for each model, like eager loading
You can do it with eager loading without loading all post. There is a method called withCount
Books.php
public function posts() {
return $this->hasMany(Post::class, 'post_id', 'id');
}
One way to find all post related to book is
$books = Books::withCount(['posts' => function ($query) use($searchTerm) {
$query->where('body', 'like', $searchTerm);
}])->get();
//How to retrieve
$book = $books->first()->posts_count.
You can find more information about withCount on laravel documentation website.
Approach 2: Without Eager Loading
$books = Books::select('*')->addSelect(DB::raw("SELECT COUNT(*) as post_count FROM `posts` WHERE `body` LIKE '%book.name%' ")->get(); //This will return collection with post_count.
Note: Not tested
Related
I'm trying to make a complex query using Laravel Eloquent. I know how to do it using raw SQL query, but I don't have any idea how to do it using Eloquent.
Here is my SQL query, and it works perfectly:
select *
from students
where exists(select *
from (select student_movements.id AS sm_id, student_movements.direction, student_movements.deleted_at
from student_movements
inner join student_student_movements
on student_movements.id = student_student_movements.student_movement_id
where students.id = student_student_movements.student_id
and student_movements.deleted_at is null
order by student_movements.id desc
limit 1) as last_sm
where last_sm.direction = 1 AND last_sm.date >= 5-5-2022
);
My models have many-to-many relation using student_student_movements table:
Student
public function studentMovements(): BelongsToMany
{
return $this->belongsToMany(
StudentMovement::class,
'student_student_movements',
);
}
StudentMovement
public function students(): BelongsToMany
{
return $this->belongsToMany(
Student::class,
'student_student_movements'
);
}
My goal is to get all Students, who have the last Movement where direction = 1 and the date of the last Movement >= $someDate.
So, my question is: how to translate the SQL query to Eloquent? I saw many similar questions, but they are not helping me.
Thanks for any advice.
Use the whereHas method, then fine tune the sub query inside the closure to your needs.
You can use the whereHas and orWhereHas methods to define
additional query constraints on your has queries.
There is an example like that in laravel documentation
use Illuminate\Database\Eloquent\Builder;
// Retrieve posts with at least one comment containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
$query->where('content', 'like', 'code%');
})->get();
// Retrieve posts with at least ten comments containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
$query->where('content', 'like', 'code%');
}, '>=', 10)->get();
check the documentation here
i want to use scope method inside join subquery so is there any way I can do that in laravel?
Post Model
public function scopePublished($query)
{
return $query->where('published',true);
}
Now I want to join user table with post table but in join I want to use this scope method directly but its giving me error.
Users::join('posts',function($q){
$q->on('posts.user_id','users.id');
$q->published();
})->get();
So is there any way I can use scope directly inside join subquery ?
First, you need to add the relation between posts and users to the User model like so:
User Model
public function posts()
{
return $this->hasMany(Post::class);
}
and then your scope stays as it is, and your query if you wanna get users with their published posts:
return User::with(['posts' => function ($query) {
$query->published();
}])
->get();
and if you want to get only users that have published posts:
return User::whereHas('posts', function ($query) {
$query->published();
})
->get();
Note that while with('posts') will include the related table's data in the returned collection, whereHas('posts') will not include the related table's data.
Hence sometimes you may need to call both together, I mean, only with('posts') will eager load relations (in this case posts).
I have the following query:
$objects = Object::with("prototypes");
As you can see I do request to model Object and join it with prototypes.
The prototypes table has structure:
prototype_id
name
How to make where in above query like as:
$objects = Object::with("prototypes")->where("prototype_id", 3);
Object model:
public function prototypes()
{
return $this->belongsToMany('App\Prototype', 'object_prototype', 'object_id');
}
Prototype model:
public function objects(){
return $this->belongsToMany("App\Object", "object_prototype", "prototype_id", "object_id");
}
If the relationship is correctly set in your Eloquent models, you can use the WhereHas function to query relationship existence.
$objects = Object::with('prototypes')
->whereHas('prototypes', function ($query) {
$query->where('prototype_id', 3);
})
->get();
Just to add on #Jerodev answer.
If you need even more power, you may use the whereHas and
orWhereHas methods to put "where" conditions on your has queries.
These methods allow you to add customized constraints to a
relationship constraint, such as checking the content of a comment:
// Retrieve all posts with at least one comment containing words like foo%
$posts = Post::whereHas('comments', function ($query) {
$query->where('content', 'like', 'foo%');
})->get();
You can read more about Eloquent Relationships
And in your case you can also construct a your query like.
Object::whereHas('prototypes', function ($query)){
$query->where('prototype_id', 3);
})->get();
I have posts table (id, user_id, title) and Post model with this content
class Post extends Model
{
public function user()
{
return $this->belongsTo('App\User');
}
}
I want to get some post by id and also the user's information, so I use this query
$post = new Post();
$res = $post->where('id', 1)->select('id', 'title', 'user_id')->with([
'user' => function ($query) {
$query->select('id', 'name', 'email');
}
])->first();
It returns the data as expected, and i can access the post's info like $res->title, or the user's info like $res->user->email, but the problem is it makes 2 queries to the database
I would expect to have one query only
SELECT
`posts`.`id`,
`posts`.`title`,
`posts`.`user_id`,
`users`.`id`,
`users`.`email`,
`users`.`name`
FROM
`posts`
LEFT JOIN `users`
ON `posts`.`user_id` = `users`.`id`
WHERE `posts`.`id` = '1'
LIMIT 1
Please note, this is not the same as N+1 problem
https://laravel.com/docs/5.3/eloquent-relationships#eager-loading
I know I can manually do left join,
$res = $post->where('posts.id', 1)
->select('posts.id', 'posts.title', 'posts.user_id', 'users.email', 'users.name')
->leftJoin('users', 'posts.user_id', '=', 'users.id')
->first();
and it will have the one query as I need, but the problem is in the result all data from related table is in the same array (and besides, what is the point of defining/using relationships if i have to manually make a left join every time)
So, my question is how to get the post data with related tables with one query and result organized according to relations: I am curious what is the best practice in laravel and how experienced Laravel developers are doing this ?
Thanks
Eloquent never uses JOINs to retrieve relationship data, but instead uses seperate queries and links the data together in PHP objects. Therefore, you will always have one extra query for each relationship. Also, Eloquent mostly loads all columns (using *).
To link them together, you have to stop using the query builder and instead use Eloquent directly:
$post = Post::find(1)->load('user');
If you insist on using JOINs, you will have to continue using the query builder.
That is eager loading.
You are using
->with([
'user' => function ($query) {
$query->select('id', 'name', 'email');
}
])
In eager loading, what happens is first run above query and get all the users matching the query.
Then the result is applied to the outer query which is
$post->where('id', 1)->select('id', 'title', 'user_id')->with([
'user' => function ($query) {
$query->select('id', 'name', 'email');
}
])->first();
I have an eloquent object Performer that has Albums and Albums have Images
Here is setup:
Model Performer->albums():
public function albums()
{
return $this->belongsToMany('Album','performer_albums','performer_id','album_id');
}
Model Album->images()
public function images()
{
return $this->belongsToMany('Image','album_images','album_id','image_id')->withPivot(['type','size']);
}
I have performer object stored as such:
$performer = Performer::where...->first();
Now I need to get Performer's Albums with images where size is 'large'
So to avoid nesting queries, can I use with()?
I tried
$performer->albums()
->with('images')
->wherePivot('size','large')
->get();
But laravel tells me it's trying to use wherePivot for Performer-Album relationship (M-2-M)
PS. I am also aware that I can do this,
$performer = Performer::with('albums')
->with('albums.images')
->.....-conditions for additional fields in album_images....
->get();
but question remains the same.
You need eager load constraints:
$performer->albums()
->with(['images' => function ($q) {
$q->wherePivot('size','large');
}])
->get();
And btw, no, you can't do this:
Performer::with('albums')
->with('albums.images')
->.....-conditions for additional fields in album_images....
->get();
instead you could do:
Performer::with(['albums.images' => function ($q) {
$q-> .....-conditions for additional fields in album_images....
}])->get();