[增添]添加了datasource的setting数据库以及默认值

vendor/filament/tables/docs/03-columns/11-relationships.md

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+---
+title: Column relationships
+---
+
+## Displaying data from relationships
+
+You may use "dot notation" to access columns within relationships. The name of the relationship comes first, followed by a period, followed by the name of the column to display:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+
+TextColumn::make('author.name')
+```
+
+## Counting relationships
+
+If you wish to count the number of related records in a column, you may use the `counts()` method:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+
+TextColumn::make('users_count')->counts('users')
+```
+
+In this example, `users` is the name of the relationship to count from. The name of the column must be `users_count`, as this is the convention that [Laravel uses](https://laravel.com/docs/eloquent-relationships#counting-related-models) for storing the result.
+
+If you'd like to scope the relationship before calculating, you can pass an array to the method, where the key is the relationship name and the value is the function to scope the Eloquent query with:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+use Illuminate\Database\Eloquent\Builder;
+
+TextColumn::make('users_count')->counts([
+    'users' => fn (Builder $query) => $query->where('is_active', true),
+])
+```
+
+## Determining relationship existence
+
+If you simply wish to indicate whether related records exist in a column, you may use the `exists()` method:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+
+TextColumn::make('users_exists')->exists('users')
+```
+
+In this example, `users` is the name of the relationship to check for existence. The name of the column must be `users_exists`, as this is the convention that [Laravel uses](https://laravel.com/docs/eloquent-relationships#other-aggregate-functions) for storing the result.
+
+If you'd like to scope the relationship before calculating, you can pass an array to the method, where the key is the relationship name and the value is the function to scope the Eloquent query with:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+use Illuminate\Database\Eloquent\Builder;
+
+TextColumn::make('users_exists')->exists([
+    'users' => fn (Builder $query) => $query->where('is_active', true),
+])
+```
+
+## Aggregating relationships
+
+Filament provides several methods for aggregating a relationship field, including `avg()`, `max()`, `min()` and `sum()`. For instance, if you wish to show the average of a field on all related records in a column, you may use the `avg()` method:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+
+TextColumn::make('users_avg_age')->avg('users', 'age')
+```
+
+In this example, `users` is the name of the relationship, while `age` is the field that is being averaged. The name of the column must be `users_avg_age`, as this is the convention that [Laravel uses](https://laravel.com/docs/eloquent-relationships#other-aggregate-functions) for storing the result.
+
+If you'd like to scope the relationship before calculating, you can pass an array to the method, where the key is the relationship name and the value is the function to scope the Eloquent query with:
+
+```php
+use Filament\Tables\Columns\TextColumn;
+use Illuminate\Database\Eloquent\Builder;
+
+TextColumn::make('users_avg_age')->avg([
+    'users' => fn (Builder $query) => $query->where('is_active', true),
+], 'age')
+```