thinkphp 3.2 視圖模型 產生的SQL語句提示 1267異常 求指點

thinkphp 3.2 視圖模型 產生的SQL語句提示 1267錯誤 求指點~
用的TP3.2 視圖模型 查詢
模型裡是這樣寫的
PicViewModel.class.php

namespace Home\Model;
use Think\Model\ViewModel;
class PicViewModel extends  ViewModel{
    public $viewFields =array(
       'Picture'=> array('picTitle','picToken','picCategroy','picAuthor','picPostTime','_as'=>'Picture'),
        'PictureAttachment' =>array('pictureid','pictureurl','creattime','_on'=>'Picture.picToken = PictureAttachment.pictureid','_as'=>'PictureAttachment'),


    );
}

控制器這樣寫

  public function  Pic(){
         $PicModel =D('PicView');    
        $s1= $PicModel->field('picTitle,picCategroy,picAuthor,picPostTime,pictureurl')->order('picPostTime desc')->select();
        dump($PicModel->getLastSql());
        dump($s1);

    }

產生的SQL 陳述式是這樣的

SELECT Picture.picTitle AS picTitle,Picture.picCategroy AS picCategroy,Picture.picAuthor AS picAuthor,Picture.picPostTime AS picPostTime,PictureAttachment.pictureurl AS pictureurl FROM xxx_picture Picture  JOIN xxx_picture_attachment PictureAttachment ON Picture.picToken = PictureAttachment.pictureid ORDER BY Picture.picPostTime desc

在phpmyadmin裡運行出現
MySQL 返回： 文檔

#1267 - Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='
這個應該是定序不同 然後我在phpmyadmin裡直接修改表的
改成一樣是utf8_general_ci,了 還是報錯

網上查了是這樣執行
alert xxx_picture_attachment CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci
ALTER xxx_picture_attachment DEFAULT CHARACTER SET utf8_general_ci
貌似也不行額
報錯
MySQL 返回： 文檔

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'alert xxx_picture_attachment CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_' at line 1

求大神指點下啊
------解決思路----------------------
貼出表結構看看

