现有生产数据库适配Laravel 5.6的最低要求及迁移咨询

Hey there! Let's break down your questions step by step since you're looking to migrate your production system to Laravel 5.6 while keeping your existing (non-standard) database.

First up, let's cover the baseline needs for your database to work with Laravel 5.6:

• Supported Database Types: Laravel 5.6 officially supports MySQL 5.7.7+, PostgreSQL 9.6+, SQL Server 2017+, and SQLite 3.8.8+. If you're using MySQL, don't skip the 5.7.7+ requirement—Laravel 5.6 relies on newer features like improved JSON field handling and proper timestamp support that older versions don't have.
• Character Set: While not strictly a "minimum" requirement, using utf8mb4 is highly recommended (it supports emojis and all Unicode characters). If your database uses utf8, it will run, but you might hit issues with storing certain characters down the line.
• User Permissions: Your database user needs core permissions like CREATE, ALTER, SELECT, INSERT, UPDATE, and DELETE. Laravel uses these for migrations, Eloquent operations, and schema management.
• Primary Keys: Ideally, every table should have an auto-incrementing primary key (usually an id column of type INT or BIGINT). Eloquent defaults to this, but if your tables don't have one, you can override it in your models with protected $primaryKey = 'your_custom_key'; and public $incrementing = false;—just be prepared for a bit more manual configuration.

reliese/Laravel is a great tool for generating Eloquent models from existing databases, even when your schema isn't perfectly compliant. Here's how to work around the missing foreign keys:

1. Install and Configure reliese/Laravel:
   • Run composer require reliese/laravel in your Laravel 5.6 project.
   • Add Reliese\Coders\CodersServiceProvider::class to the providers array in config/app.php (Laravel 5.6 doesn't auto-discover this package by default).
2. Generate Base Models:
   • Run php artisan code:models—this will scan your database and generate basic Eloquent models with correct fillable fields, hidden attributes, and timestamp settings (it'll even detect non-standard timestamp column names if you have them).
3. Manually Add Relationships:
   • Since there are no foreign key constraints, reliese can't auto-detect relationships. You'll need to map them manually based on your database's logical structure. For example:
     • If your orders table has a customer_id that links to customers.id, add this to your Order model:

       public function customer()
       {
           return $this->belongsTo(Customer::class, 'customer_id');
       }
       

     • And in your Customer model:

       public function orders()
       {
           return $this->hasMany(Order::class, 'customer_id');
       }
       

   • Don't forget to adjust model properties if your tables/fields don't follow Laravel's naming conventions (e.g., singular table names). For a table named customer instead of customers, add protected $table = 'customer'; to your Customer model.

• Test Locally First: Clone your production database to a local environment, generate your models, and test all core operations (queries, creates, updates, deletes) to make sure Eloquent behaves the same way as your original system.
• Migrate Gradually: Instead of swapping out your entire production system at once, migrate one feature or module at a time. This reduces risk and lets you iron out kinks without disrupting users.
• Fix Constraints When Possible: If you can safely do so (after backing up your database), gradually add missing foreign key constraints. This will make your database more reliable, simplify future maintenance, and let Laravel handle relationships more seamlessly.

内容的提问来源于stack exchange，提问作者IgorAlves