check query no result in laravel 5.5

Question

I would like to find a way to check if my query result doesn't return a value. Example: If in my tableExample on database there isn' t the id that I'm passing , the method should return an exception or a simple echo that indicate me the not presence in the table

My code below:

try{
     DB::table('tableExample')
        ->where('id', "2")
        ->update(['update' => "1"]);

        return $result= array("result" => "true" );
      }catch(QueryException $e){
        return $result= array("result" => "false" );
        echo " - ".$e;
      }
}

Answer 1

update method return integer value ( affected rows ) if success, try like this

try{
    $update = DB::table('tableExample')
        ->where('id', "2")
        ->update(['update' => "1"]);
    if($update){
        $result = array("result" => true );
    }else{
        $result = array("result" => false,"message"=>"Not Found" );
    }
}catch(QueryException $e){
    $result = array("result" => false,"message"=>$e->getMessage() );
}
return $result;

Answer 2

Use findOrFail() helper method. That way you do not need to wrap the action in a try catch since if findOrFail does not find the row then it will throw an exception.

    $resultData = DB::table('tableExample')->findOrFail(2);

    $update = $resultData->update(['update' => "1"]);

    if(!$update){
      return response(['results'=>false]);
    }

    return response(['results'=> true]); 

}

update() method returns a boolean true for success on update and versa.

Answer 3

You can do this by using the whereExists clause:

https://laravel.com/docs/5.5/queries#where-exists-clauses

https://laravel.com/api/5.5/Illuminate/Database/Query/Builder.html#method_exists