Laravel: Where is the Choice for Eloquent Eager Loading Relations
I have two DB tables:
Posts
$table->increments('id');
$table->integer('country_id')->unsigned();
$table->foreign('country_id')->references('id')->on('countries');
Country
$table->increments('id');
$table->string('name', 70);
I am using laravel as back-end. Now I want to implement filtering data for my interface. This way the user can select the country name and laravel has to respond to the request with only posts that have a country with the given name.
How can I add this condition to an existing pagination query? I've tried this:
$query = app(Post::class)->with('country')->newQuery();
// ...
if ($request->exists('country')) {
$query->where('country.name', $request->country);
}
// ...
... results in the following error:
Column not found: 1054 Unknown column 'country.name' in 'where clause' (SQL: select count(*) as aggregate from `posts` where `country`.`name` = Albania)
+3
source to share
2 answers
whereHas method takes a parameter according to Laravel code base,
/**
* Add a relationship count / exists condition to the query with where clauses.
*
* @param string $relation
* @param \Closure|null $callback
* @param string $operator
* @param int $count
* @return \Illuminate\Database\Eloquent\Builder|static
*/
public function whereHas($relation, Closure $callback = null, $operator = '>=', $count = 1)
{
return $this->has($relation, $operator, $count, 'and', $callback);
}
so by changing the code a little,
$query = ""
if ($request->has('country'){
$query = Post::with("country")->whereHas("country",function($q) use($request){
$q->where("name","=",$request->country);
})->get()
}else{
$query = Post::with("country")->get();
}
By the way, the above code can be simplified a bit as follows:
$query = ""
if ($request->has('country'){
$query = Post::with(["country" => function($q) use($request){
$q->where("name","=",$request->country);
}])->first()
}else{
$query = Post::with("country")->get();
}
+5
source to share