1. in-depth understanding of LaravelEloquent (1)-Basic concepts and usage

1. in-depth understanding of LaravelEloquent (1) -- Basic concepts and usage: find the article with id 2 and print its title

$article = Article::find(2);echo $article->title;

Search for the article titled "I am the title" and print the id

$ Article = Article: where ('title', 'I am title')-> first (); echo $ article-> id;

Query all articles and print all titles cyclically

$ Articles = Article: all (); // The $ articles obtained here is a collection of objects. you can add '-> toArray ()' to the end of the object to change it to a multi-dimensional array. Foreach ($ articles as $ article) {echo $ article-> title ;}

The search id ranges from 10 to 10 ~ All articles between 20 and print all titles

$articles = Article::where('id', '>', 10)->where('id', '<', 20)->get(); foreach ($articles as $article) {         echo $article->title; }

Query all articles and print all titles cyclically. Sort by updated_at in reverse order.

$articles = Article::where('id', '>', 10)->where('id', '<', 20)->orderBy('updated_at', 'desc')->get(); foreach ($articles as $article) {     echo $article->title; }

Basic usage points

1. each class that inherits Eloquent has two 'fixed use' Article: find ($ number) ''' Article: all ()', the former will get an object with the value obtained from the database, and the latter will get a collection of objects containing the entire database.

2. all intermediate methods, such as 'Where () ''' orderBy () ', support both 'static' and 'non-static chains', that is, 'Article :: where ()... 'and 'article ::.... -> where ()'.

3. all 'unfixed use' calls require an operation to 'finalize'. There are two 'final operation' in this tutorial: '-> get () 'and'-> first ()'.

4. if you do not understand why many methods such as '-> where () ''-> get ()' can be used in the 'article' class, you need to read the document on object inheritance in PHP: object inheritance.