Thinkphp5.1 model associated with the query output the whole took a long time to understand, to be a note

1. First on the table and model

1.user user table 
{ 
　　user_id // Primary 
} 
2.account accounts table 
{ 
　　ACCOUNT_ID // primary key 
　　user_id // foreign key user 
} 

3.User model 
class the User the extends the Model 
{ 
   protected  $ Table = 'yh_user' ;
    protected  $ PK = 'user_id' ; 
} 
4.Account model 
class Account the extends the model 
{ 
   protected  $ Table = 'yh_account' ;
    protected  $ PK = 'ACCOUNT_ID' ; 
} 

a, if necessary data is acquired by the User Account model models the first step User model Note that many methods created in association are:hasMany () method

class User extends Model
{
 protected $table = 'yh_user';
 protected $pk = 'user_id';

　//关键操作
 public function account()
 {
 return $this->hasMany('Account','user_id');
 }

 }

Controller Operation

$data = UserModel::with('account')->select();

Output:

[2] => Array (. 3) { 
    [ "user_id"] => int (67) 
    [ "Account"] => Array (. 1) { 
      [0] => Array (2) { 
        [ "ACCOUNT_ID"] => int (. 1) 
        [ "user_id"] => int (67) 
      } 
    } 


a, if necessary to obtain the data model User Account first step anti-models created by the model association method is associated Account Note: a belongsTo () method

class Account extends Model
{
 protected $table = 'yh_account';
 protected $pk = 'account_id';

//关键操作
 public function User()
 {
 return $this->belongsTo('User','user_id');
 }
}

Controller operation:

Data $ = AccountModel :: with ( 'the User' ) -> SELECT () ; 
the dump ( $ Data ) ;
 output:

array(1) {
  [0] => array(8) {
    ["account_id"] => int(1)
    ["user_id"] => int(67)
    ["user"] => array(11) {
      ["user_id"] => int(67)
    }
  }
}