How to use nested Where functions in Laravel

This article summarizes the ways to use nested `where` functions in Laravel, helping readers understand how to construct complex queries in their applications.

Laravel provides various methods to utilize nested where functions in database queries. Using nested where allows you to create more complex conditions, enhancing the accuracy and efficiency of data retrieval. Below are some common ways to implement nested where functions in Laravel.

Ways to Use Nested Where Functions in Laravel:

1. Using Nested Where with Closure:

   $users = DB::table('users')
       ->where('status', 'active')
       ->where(function ($query) {
           $query->where('age', '>', 18)
                 ->orWhere('role', 'admin');
       })
       ->get();
   

2. Using Nested Where with Multiple Conditions:

   $products = DB::table('products')
       ->where('category', 'electronics')
       ->where(function ($query) {
           $query->where('price', '<', 1000)
                 ->where('stock', '>', 0);
       })
       ->get();
   

3. Using Nested Where with Multiple Tables:

   $orders = DB::table('orders')
       ->where('status', 'completed')
       ->where(function ($query) {
           $query->whereExists(function ($query) {
               $query->select(DB::raw(1))
                     ->from('order_items')
                     ->whereRaw('order_items.order_id = orders.id')
                     ->where('order_items.quantity', '>', 0);
           });
       })
       ->get();
   

4. Using Nested OrWhere:

   $users = DB::table('users')
       ->where('active', 1)
       ->orWhere(function ($query) {
           $query->where('email_verified_at', '!=', null)
                 ->where('created_at', '>', now()->subYear());
       })
       ->get();
   

5. Using Nested Where in Eloquent:

   $posts = Post::where('status', 'published')
       ->where(function ($query) {
           $query->where('views', '>', 100)
                 ->orWhere('likes', '>', 50);
       })
       ->get();
   

System requirements:

• Laravel 5.1 or higher
• Development environment set up and configured

Tips:

• Use nested where when dealing with multiple complex conditions for better management and readability of your code.
• Always check and optimize queries to avoid slowing down your application.

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