循环内循环数组

Question

基于此Mongoose embedded documents / DocumentsArrays id 我尝试在循环内的循环中实现条件。最后，新的“tosave”评论对象应该包含来自 BlogPost 基于“where a_id = b_id”的_id。

我使用节点、快递和猫鼬。 我有一个包含多个博客帖子的多行表单，一个博客帖子可以有多个评论。

在后端，我有 2 个数组 -> 像这样的博客帖子和评论：

BlogPosts: [{ a_id: '1', name: 'name1' },
            { a_id: '2', name: 'name2' },
            { a_id: '3', name: 'name3' }], 


Comments: [{ b_id: '1', name: 'comment for BlogPost name1' },
           { b_id: '1', name: 'other comment for BlogPost name1' },
           { b_id: '3', name: 'comment for BlogPost name3' }],

我需要每个评论中的博客文章文档中的 _id，以便在评论和博客文章之间进行引用。

我像这样遍历博客帖子：

var new_post_to_save = [];

    for(var i=0; i<req.body.blogposts.length;i++) {

       var newpost = new BlogPost();

       console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );

       newpost.name = req.body.blogposts[i].name,
       newpost.a_id = req.body.blogposts[i].a_id

       new_post_to_save.push(newpost);

     },

这工作正常。我得到一个新数组“new_post_to_save”，我可以轻松保存。 现在我尝试在 BlogPosts 中循环，为每个评论提供来自新创建的“newpost”对象的 _id 字段。

我尝试了什么 - 但它失败了。它匹配所有博客帖子的所有评论。

var new_post_to_save = [];
var new_comment_to_save = [];

     for(var i=0; i<req.body.blogposts.length;i++) {

       var newpost = new BlogPost();

       console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );

       newpost.name = req.body.blogposts[i].name,
       newpost.a_id = req.body.blogposts[i].a_id

       // here a loop to create x Comments with the _id from newpost and 
       // the condition: IF a_id = b_id 
       // then create new Comment and get die _id from his Blogpost

       for(var f=0; f<req.body.comments.length;f++) {

         if (newpost.a_id = req.body.comments[f].b_id) 
         console.log(' Yea ! Comment ' + [f] + ' matches Blogpost Nr. ' + [i]);

          var newcomment = new CommentModel();

          newcomment.id_newpost = newpost._id,
          newcomment.name = req.body.comments[f].name,
          newcomment.b_id = req.body.comments[f].b_id,       
        };  // end if
     };   // end for


    new_comment_to_save.push(newcomment);
    new_post_to_save.push(newpost);

      },    // end for

这是我的第一个问题。

有什么想法吗？非常感谢

Answer 1

我不熟悉Mongoose，只是看你的代码，似乎你的代码有一点错误： position of: new_comment_to_save.push(newcomment);它应该在 if 中，因为只有当它们匹配时，您才希望添加它们..

var new_post_to_save = [];
var new_comment_to_save = [];
 for(var i=0; i<req.body.blogposts.length;i++) {

   var newpost = new BlogPost();

   console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );

   newpost.name = req.body.blogposts[i].name,
   newpost.a_id = req.body.blogposts[i].a_id

   // here a loop to create x Comments with the _id from newpost and 
   // the condition: IF a_id = b_id 
   // then create new Comment and get die _id from his Blogpost

   for(var f=0; f<req.body.comments.length;f++) {

     if (newpost.a_id = req.body.comments[f].b_id) 
     console.log(' Yea ! Comment ' + [f] + ' matches Blogpost Nr. ' + [i]);

      var newcomment = new CommentModel();

      newcomment.id_newpost = newpost._id,
      newcomment.name = req.body.comments[f].name,
      newcomment.b_id = req.body.comments[f].b_id,
      new_comment_to_save.push(newcomment);       
    };  // end if
 };   // end for



new_post_to_save.push(newpost);

  },    // end for