Question

    CREATE TABLE post_likes (
       post_id                INT NOT NULL, 
       user_id                INT NOT NULL, 
       likes                  BOOLEAN NOT NULL,         
       FOREIGN KEY            (post_id) REFERENCES posts(id),
       FOREIGN KEY            (user_id) REFERENCES users(id),
       PRIMARY KEY            (user_id, post_id) 
    )


    +-------+---------+---------+
    | likes | post_id | user_id |
    +-------+---------+---------+
    |     1 |       1 |       1 |
    |     1 |       1 |       2 |
    |     0 |       2 |       1 |
    |     0 |       2 |       2 |
    +-------+---------+---------+

我使用NodeJS和EJS作为模板语言。现在我将表post_likes传递给我的EJS。并尝试做一个for循环。基本上在表1 =真或喜欢，0 =假或不喜欢。所以我有一个计数器，如果它像我一样反对++ else counter--。但它看起来很糟糕。它也因某种原因不起作用什么是更好的方法。

我尝试了什么 - 我排除了不需要的代码的其他部分。我删除了关闭括号的ejs并打开以使其更具可读性。

<% var counter = 0 %>

for(var i = posts.length-1; i >= 0; i--) {
     if(posts[i].post_likes.length > 0) { 
        for(var j = 0; j < posts[i].post_likes.length; j++) { 
             if(posts[i].post_likes[j].likes == true) { 
                 counter = counter + 1 %>
             } 
             else if(posts[i].post_likes[j].likes == false) { 
                 counter = counter - 1 
             } 
         } 
     } 
}

<h1><%= counter %></h1>

Answer 1

你可以做这样的事情来获得喜欢和不喜欢的帖子。

var posts = [{
    post_likes: [{
        likes: true
    }]
}, {
    post_likes: [{
        likes: true
    }]
}, {
    post_likes: [{
        likes: false
    }]
}, {
    post_likes: [{
        likes: true
    }]
}];

var likedPosts = 0;
var unlikedPosts = 0;

posts.forEach(function(post) {
    likedPosts += post.post_likes.filter(function(v) {
        return v.likes === true;
    }).length;

    unlikedPosts += post.post_likes.filter(function(v) {
        return v.likes === false;
    }).length;
});

console.log('Liked posts: ' + likedPosts);
console.log('Unliked posts: ' + unlikedPosts);

如何显示喜欢/不喜欢的MySQL，NodeJS

1 个答案: