如何获取关联表'；s行急切加载:Laravel 5.1 - How to get associated table's rows in eager loading: Laravel 5.1

我有三个数据库表

CREATE TABLE `tblproject` (
  `ProjectID` int(11) NOT NULL,
  `ProjectStatusID` varchar(30) NOT NULL,
) ENGINE=InnoDB DEFAULT CHARSET=latin1; 
CREATE TABLE `tblprojectSkills` (
  `ProjectSkillID` int(11) NOT NULL,
  `ProjectID` int NOT NULL,
  `SkillID` int NOT NULL,
) ENGINE=InnoDB DEFAULT CHARSET=latin1; 
CREATE TABLE `tblSkills` (
  `SkillID` int(11) NOT NULL,
  `Skill` varchar(100) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

在上表中。CCD_ 1在CCD_ 2和CCD_。ProjectID在Project和projectSkills表中相关

我的项目模型如下

class Project_Model extends Model
{
    protected $table = "tblproject";
    protected $primaryKey = "ProjectID";
    public $timestamps = false;
    public function ProjectSkills() {
        return $this->hasMany(''App'Models'ProjectSkill_Model', 'ProjectID');
    }        
}
class ProjectSkill_Model extends Model
{
    protected $table = "tblprojectskill";
    protected $primaryKey = "ProjectSkillID";
    public $timestamps = false;
}
class Skill_Model extends Model
{
    protected $table = "tblskill";
    protected $primaryKey = "SkillID";
    public $timestamps = false;
}

下面是laravel 5.1中的数据库查询

'App'Models'Project'Project_Model
::with('ProjectSkills')
->where('ProjectID', '=', $ProjectID)->first();

问题

我可以获得技能ID，但是，如何从技能表中获得技能名称？

因此，您的验证将在每个事件、focusout等上生效。因此，我添加了以下行，以便只有在单击button:之后才能进行验证

onfocusout: false,
onkeyup: false,
onclick: false,

其次，在您的CreateErrorMessage中，我做了一些小的更改，以便同时显示所有错误消息。SkillID0是object，会有多条错误消息，因此需要经过$.each。

最后，您在循环内部检查ErrorMessages，理想情况下应该在循环外部，这样检查只发生一次。

以下是更新后的代码：

$(function() {
  $("form#loginForm").validate({
    onfocusout: false,
    onkeyup: false,
    onclick: false,
    rules: {
      EmailAddress: "required",
      Password: "required"
    },
    messages: {
      EmailAddress: {
        required: "Please enter email"
      },
      Password: {
        required: "Please enter Password"
      }
    },
    showErrors: function(errorMap, errorList) {
      RemoveErrorElements();
      CreateErrorMessage(errorList);
    }
  });
});
function CreateErrorMessage(errorList) {
  if ($(".panel-body").find("ul.ErrorMessages").length === 0) {
    $(".panel-body").prepend("<ul class='ErrorMessages'><ul>");
  }
  var ErrorMessages = $(".panel-body").find("ul.ErrorMessages");
  $.each(errorList, function(index, Message) {
    $(Message.element).parent().parent().addClass("has-error");
    $(Message).each(function(k, v) {
      ErrorMessages.append("<li>" + v.message + "</li>");
    })
  });
}
function RemoveErrorElements() {
  $(".panel-body").find("ul.ErrorMessages").remove();
}

<!DOCTYPE html>
<html>
<head>
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.17.0/jquery.validate.js"></script>
  <script src="script.js"></script>
</head>
<body>
  <div class="container">
    <div class="row">
      <div class="col-md-8 col-md-offset-2">
        <div class="panel panel-default">
          <div class="panel-heading">Login</div>
          <div class="panel-body">
            <form id="loginForm" class="form-horizontal form-label-left" novalidate="novalidate">
              <input name="_token" type="hidden" value="qZuutEkhKvETtiuA3stgpOyOiH7FrKXUPz7C7bxe">
              <div class="form-group has-error">
                <label for="EmailAddress" class="col-md-4 control-label">UserName / E-Mail Address</label>
                <div class="col-md-6">
                  <input name="EmailAddress" type="text" class="form-control">
                </div>
              </div>
              <div class="form-group has-error">
                <label for="Password" class="col-md-4 control-label">Password</label>
                <div class="col-md-6">
                  <input name="Password" type="password" value="" class="form-control">
                </div>
              </div>
              <div class="form-group">
                <div class="col-md-8 col-md-offset-4">
                  <button type="submit" class="btn btn-primary">
                                            Login
                                        </button>
                </div>
              </div>
            </form>
          </div>
        </div>
      </div>
    </div>
  </div>
</body>
</html>

class Project_Model extends Model
{
    protected $table = "tblproject";
    protected $primaryKey = "ProjectID";
    public $timestamps = false;
    public function ProjectSkills() {
        return $this->hasMany(''App'Models'ProjectSkill_Model', 'ProjectID');
    }        
}
class ProjectSkill_Model extends Model
{
    protected $table = "tblprojectskill";
    protected $primaryKey = "ProjectSkillID";
    public $timestamps = false;

    public function Skills() {
        return $this->hasOne(''App'Models'Skill_Model', 'ProjectSkillID');
    }
}
class Skill_Model extends Model
{
    protected $table = "tblskill";
    protected $primaryKey = "SkillID";
    public $timestamps = false;
}

获取技能名称

$project_info = 'App'Models'Project'Project_Model->where('ProjectID', '=', $ProjectID)->first();
foreach($project_info->ProjectSkills as $ProjectSkills) {
     dd($ProjectSkills->skill_name);
}

正如您粘贴的那样，您不需要中间表。并添加一个外键ProjectID引用tblproject表。

更改Project_Model中的关系方法，如下所示：

public function Skills() {
    return $this->hasMany(''App'Models'Skill_Model', 'ProjectID');
}

并执行查询语句：

$project = 'App'Models'Project'Project_Model::where('ProjectID', $ProjectID)->with(['Skills' => function ($query) {
    $query->addSelect(['SkillID', 'Skill', 'ProjectID']);
}])->get();