Django personal blog building --8-- article classification query

Preface ：

The front home page article display can only show all the articles in one brain , The article class of the background database is not classification Exhibition
Now I will show the background articles by category , But before we do that , I need to know what kind of articles my back-end database has , Here is an example of how many types of navigation bars there are ： Selected articles 、django Class article 、 Data analysis articles 、 There are four types of important articles , When you click one of the buttons in the navigation bar , You can see all the articles of that type

Code implementation ：

First, let's configure the routing ：

Everyone should know what this means , Corresponding , Need to be in urls.py Add four lines of code ：

After adding these four lines of code, start to write the view function
There is one method we have used many times , That's it filter Method

articleList = Article.objects.filter(category=2)

This means taking out the background Article In the table category（ classification ） In the first 2 The data of

This is my category surface , according to id To take a value .

• Why can't you use category=' Data analysis ' To get the value ？
  Because we use Article Table to query ,Article In the table category Belongs to foreign key , We should use the primary key in the foreign key （id） To query data
• Why can't you use Category Table to query ？
  because Category The data in the table is only the data of various categories , Pictured above , And we use Article.objects.filter(category=2) What such a statement finds out is category=2 The article