/**
  * @return \yii\db\ActiveQuery
  */
 public function getPost()
 {
     return $this->hasOne(Posts::className(), ['PostID' => 'PostID']);
 }
 /**
  * @return \yii\db\ActiveQuery
  */
 public function getPosts()
 {
     return $this->hasMany(Posts::className(), ['PostID' => 'PostID'])->viaTable('PostTags', ['TagID' => 'TagID']);
 }