I have existing data in the database, and I want to create a one-to-many relationship. How can I limit or simulate a one-to-many relationship when I'm using a pivot table?
I want to get the data from the pivot table, so I thought it could be done like this.
class Asset extends Model {
public function publisher() {
return $this->belongsTo(Publisher::class, 'asset_publisher');
}
}
-
class Publisher extends Model {
public function assets() {
return $this->hasMany(Asset::class, 'asset_publisher');
}
}
A possible way to simulate the one-to-many is creating a model for the pivot table "AssetPublisher" so you will now have
class Publisher extends Model {
public function assets() {
return $this->belongsToMany(Asset::class, 'asset_publisher');
}
}
class AssetPublisher extends Model {
public function publisher() {
return $this->belongsTo(Publisher::class);
}
}
class Asset extends Model {
public function assetPublisher() {
return $this->hasOne(AssetPublisher::class)->with('publisher');
}
public function getPublisherAttribute(){
return $this->assetPublisher->publisher;
}
}
You can now call $asset->publisher to give you the Publisher instance and $publisher->assets()->get() to get all assets instances
Related
I have three tables:
comments
id
comment_links
id | comment_id | link_id
links
id
I want to get all Links associated with each Comment. As you can see, CommentLink should act as a pivot table, but I don't know how to set up the relationships to make this work. I think I need to use the hasManyThrough relationship, but I'm not 100% sure.
Here are my current class relationships (they may be wrong):
Comment.php:
class Comment extends Model
{
public function commentLinks()
{
return $this->hasMany('App\CommentLink', 'comment_id', 'id');
}
public function links()
{
// How do I fetch all links here using the pivot table?
}
}
CommentLink.php:
class CommentLink extends Model
{
public function comment()
{
return $this->belongsTo('App\Comment');
}
public function link()
{
return $this->hasOne('App\Link', 'id', 'link_id');
}
}
Link.php:
class Link extends Model
{
public function commentLinks()
{
return $this->belongsToMany('App\CommentLink', 'link_id', 'id');
}
}
What do I need to do here to make this work?
You have the right idea, just using the wrong class names.
class Link extends Model
{
public function comments()
{
return $this->belongsToMany('App\Comment');
}
}
class Comment extends Model
{
public function links()
{
return $this->belongsToMany('App\Link');
}
}
You don't actually need to have a class for your pivot table, but you can if you want.
This is quite a good guide on how to do this.
https://laraveldaily.com/pivot-tables-and-many-to-many-relationships/
I am finding some difficulties to bind one relationship table to my second database.
In "db_main" I have tables, with the basic details about each object and than I have other tables: "db_site1", "db_site2" etc, in which tables I save detailed information about the same objects.
Everything is working find with that schema, except one situation in that I have relationship table (bookmaker_games), which must be only on "db_main". The table save the relations between bookmakers and games.
On my website1 I want to list the games of a bookmaker with the following models:
class Bookmaker extends Model {
public function games() {
// here the database is "db_site1"
return $this->belongsToMany('App\Models\Game', 'bookmaker_games', 'bookmaker_id', 'game_id');
}
}
class Game extends Model {
public function bookmakers() {
// here the database is "db_site1"
return $this->belongsToMany('App\Models\Bookmaker', 'bookmaker_games', 'game_id', 'bookmaker_id');
}
}
class BookmakerGame extends Model {
protected $connection = 'db_main';
}
When I try to return all games, it is thinking that "bookmaker_games"-table is on database "db_site1", which is wrong.
What is the best way to tell that relationship to look at the correct database ?
Declare BookmakerGame as a subclass of Illuminate\Database\Eloquent\Relations\Pivot
Then define the relationships to use it.
Prefixing the connection name
//...
use Illuminate\Database\Eloquent\Relations\Pivot;
class Bookmaker extends Model {
public function games() {
// here the database is "db_site1"
return $this->belongsToMany(
'App\Models\Game', 'db_main.bookmaker_games', 'bookmaker_id', 'game_id')
->using('App\Models\BookmakerGame');
}
}
class Game extends Model {
public function bookmakers() {
// here the database is "db_site1"
return $this->belongsToMany(
'App\Models\Bookmaker', 'db_main.bookmaker_games', 'game_id', 'bookmaker_id')
->using('App\Models\BookmakerGame');
}
}
class BookmakerGame extends Pivot {
protected $connection = 'db_main';
}
Using the class path to the pivot
use Illuminate\Database\Eloquent\Relations\Pivot;
class Bookmaker extends Model {
public function games() {
// here the database is "db_site1"
return $this->belongsToMany(
'App\Models\Game', 'App\Models\BookmakerGame', 'bookmaker_id', 'game_id');
}
}
class Game extends Model {
public function bookmakers() {
// here the database is "db_site1"
return $this->belongsToMany(
'App\Models\Bookmaker', 'App\Models\BookmakerGame', 'game_id', 'bookmaker_id');
}
}
class BookmakerGame extends Pivot {
protected $connection = 'db_main';
protected $table = 'bookmaker_games';
}
There are 2 tables and 2 models. Table "games" has 2 foreign keys "team_a_id" and "team_b_id"
I try to define relationship but can't understand how build this relationship. One game can have only one team A and only one team B. But one team can have many games.
At this moment I have
class Game extends Model
{
public function teamA()
{
return $this->hasOne('App\Models\Team', 'team_a_id');
}
public function teamB()
{
return $this->hasOne('App\Models\Team', 'team_b_id');
}
}
and
class Team extends Model
{
public function gameTeamA()
{
return $this->belongsTo('App\Models\GameSerie', 'team_a_id');
}
public function gameTeamB()
{
return $this->belongsTo('App\Models\GameSerie', 'team_b_id');
}
}
I have to define relationship in order to find all games where team was team_a or team_b.
e.g.
$allGames = $team->games($id);
Also i am not sure that i defined relationships right
It's the other way around. The model with the foreign key has the BelongsTo relationship:
class Game extends Model
{
public function teamA()
{
return $this->belongsTo('App\Models\Team', 'team_a_id');
}
public function teamB()
{
return $this->belongsTo('App\Models\Team', 'team_b_id');
}
}
class Team extends Model
{
public function gameTeamA()
{
return $this->hasOne('App\Models\GameSerie', 'team_a_id');
}
public function gameTeamB()
{
return $this->hasOne('App\Models\GameSerie', 'team_b_id');
}
}
I have a recently started learning Laravel 5.4, I am having trouble with my 3 way table relationship, I've looked at a few articles online regarding many to many, but this relationship is just a "hasOne" on both sides.
Could anyone give me a helpful hint as to how to structure my table relationship, here is the PK/FK relationship:
Users table (id)
Listings table (id, user_id)
Insights table (id, listing_id) - one insight row per listing only.
And the models below:
Users Model
class User extends Model
{
public function listing()
{
return $this->belongsTo('App\Listing');
}
}
Listing Model
class Listing extends Model
{
public function insight()
{
return $this->hasOne('App\Insight');
}
}
Insight Model
class Insight extends Model
{
public function listing()
{
return $this->hasOne('App\Listing');
}
}
And what I am trying to achieve is to query the users own listings, with each listings current insights.
Thanks a bunch.
Simon.
User model
class User extends Model
{
public function listing()
{
return $this->hasOne('App\Listing');
}
}
Listing Model
class Listing extends Model
{
public function insight()
{
return $this->hasOne('App\Insight');
}
public function user()
{
return $this->belongsTo('App\User');
}
}
Insight Model
class Insight extends Model
{
public function listing()
{
return $this->belongsTo('App\Listing');
}
}
And if you want query users with Listing and Insight
$users = User::with(['listing', 'listing.insight'])->get();
foreach($users as $user) {
$user->listing->insight;
}
class User extends Model
{
public function listing()
{
return $this->hasMany(Listing::class);
}
}
class Listing extends Model
{
public function insight()
{
return $this->hasOne(Insight::class);
}
public function user()
{
return $this->belongsTo(User::class);
}
}
class Insight extends Model
{
public function listing()
{
return $this->belongsTo(Listing::class);
}
}
$users = User::with('listing.insight')->get();
foreach($users as $user) {
$user->listing->insight;
}
I have the following database tables:
Seasons
id
number
Teams
id
name
Standings
id
season_id
team_id
The question is, how could I get all of the teams in a season through the standings table. At the moment I am getting all of the teams this way:
$teams = [];
$standings = $season->standings;
foreach($standings as $standing){
$teams[] = $standing->team;
}
Is there a way I could do this using Eloquent relationships? I have tried HasManyThrough with no success. These are what my models look like currently:
class Season extends Eloquent{
public function standings(){
return $this->hasMany('Standing');
}
}
class Standing extends Eloquent{
public function team(){
return $this->belongsTo('Team');
}
}
class Team extends Eloquent{
public function standings(){
return $this->belongsToMany('Standing');
}
}
Your relationships look a little off. Here is all the relationships you should need though only the belongsToMany ones are required for this specific scenario of finding all the teams in a season.
class Season extends Eloquent {
public function teams()
{
return $this->belongsToMany('Team', 'Standings');
}
public function standings()
{
return $this->hasMany('Standing');
}
}
class Team extends Eloquent {
public function seasons()
{
return $this->belongsToMany('Season', 'Standings');
}
public function standings()
{
return $this->hasMany('Standing');
}
}
class Standing extends Eloquent {
public function team()
{
return $this->belongsTo('Team');
}
public function season()
{
return $this->belongsTo('Season');
}
}
You would use the belongsToMany relationship rather than a hasManyThrough to query all the teams in a season. That would look something like...
Season::with('teams')->find($season_id);
foreach($season->teams as $team) {
echo $team->name;
}