零框架多租户设计方案

samples/MultiTenancySample/MultiTenancySample.FieldIsolationService/EntityFrameworks/DataSeeding.cs

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+using Microsoft.EntityFrameworkCore;
+using MultiTenancySample.FieldIsolationService.Entities;
+using MultiTenancySample.ServiceDefaults;
+
+namespace MultiTenancySample.FieldIsolationService.EntityFrameworks
+{
+    public class DataSeeding(IDbContextFactory<FieldIsolationServiceDbContext> dbContext, ICurrentTenant currentTenant)
+    {
+        public async Task SeedDataAsync()
+        {
+            currentTenant.SetTenant("Tenant1");
+
+            FieldIsolationServiceDbContext dbContext1 = await dbContext.CreateDbContextAsync();
+
+            if (await dbContext1.Database.EnsureCreatedAsync())
+            {
+                await dbContext1.AddRangeAsync(new List<Product> {
+                    new() { Id = Guid.NewGuid(), Name = "Product1"},
+                    new() { Id = Guid.NewGuid(), Name = "Product3"},
+                    new() { Id = Guid.NewGuid(), Name = "Product5"}
+                });
+
+                await dbContext1.SaveChangesAsync();
+            }
+
+            currentTenant.SetTenant("Tenant2");
+
+            FieldIsolationServiceDbContext dbContext2 = await dbContext.CreateDbContextAsync();
+
+            if (await dbContext2.Set<Product>().IgnoreQueryFilters().CountAsync() < 6)
+            {
+                await dbContext2.AddRangeAsync(new List<Product>
+                {
+                    new() { Id = Guid.NewGuid(), Name = "Product2"},
+                    new() { Id = Guid.NewGuid(), Name = "Product4"},
+                    new() { Id = Guid.NewGuid(), Name = "Product6"}
+                });
+
+                await dbContext2.SaveChangesAsync();
+            }
+        }
+    }
+}

samples/MultiTenancySample/MultiTenancySample.FieldIsolationService/EntityFrameworks/EntityTypeBuilderQueryFilterExtensions.cs

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+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Microsoft.EntityFrameworkCore.Query;
+using System.Linq.Expressions;
+
+namespace MultiTenancySample.FieldIsolationService.EntityFrameworks
+{
+    public static class EntityTypeBuilderQueryFilterExtensions
+    {
+        /// <summary>
+        /// Support multiple HasQueryFilter calls on same entity type
+        /// https://github.com/dotnet/efcore/issues/10275
+        /// </summary>
+        public static void AddQueryFilter<T>(this EntityTypeBuilder entityTypeBuilder, Expression<Func<T, bool>> expression)
+        {
+            ParameterExpression parameterType = Expression.Parameter(entityTypeBuilder.Metadata.ClrType);
+            Expression expressionFilter = ReplacingExpressionVisitor.Replace(expression.Parameters.Single(), parameterType, expression.Body);
+
+            LambdaExpression? currentQueryFilter = entityTypeBuilder.Metadata.GetQueryFilter();
+            if (currentQueryFilter is not null)
+            {
+                Expression currentExpressionFilter = ReplacingExpressionVisitor.Replace(currentQueryFilter.Parameters.Single(), parameterType, currentQueryFilter.Body);
+                expressionFilter = Expression.AndAlso(currentExpressionFilter, expressionFilter);
+            }
+
+            LambdaExpression lambdaExpression = Expression.Lambda(expressionFilter, parameterType);
+            entityTypeBuilder.HasQueryFilter(lambdaExpression);
+        }
+    }
+}

samples/MultiTenancySample/MultiTenancySample.FieldIsolationService/EntityFrameworks/FieldIsolationServiceDbContext.cs

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+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata;
+using MultiTenancySample.FieldIsolationService.Entities;
+using MultiTenancySample.ServiceDefaults;
+
+namespace MultiTenancySample.FieldIsolationService.EntityFrameworks
+{
+    public class FieldIsolationServiceDbContext(DbContextOptions<FieldIsolationServiceDbContext> options, ICurrentTenant currentTenant) : DbContext(options)
+    {
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<Product>().Property(p => p.Name).HasMaxLength(32);
+
+            foreach (IMutableEntityType entityType in modelBuilder.Model.GetEntityTypes())
+            {
+                if (entityType.ClrType.IsAssignableTo(typeof(IMultiTenant)))
+                {
+                    modelBuilder.Entity(entityType.ClrType).AddQueryFilter<IMultiTenant>(e => e.TenantId == currentTenant.TenantId);
+                }
+            }
+
+            base.OnModelCreating(modelBuilder);
+        }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.AddInterceptors(new TenantSaveChangesInterceptor(currentTenant));
+
+            base.OnConfiguring(optionsBuilder);
+        }
+    }
+}

samples/MultiTenancySample/MultiTenancySample.FieldIsolationService/EntityFrameworks/TenantSaveChangesInterceptor.cs

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+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.ChangeTracking;
+using Microsoft.EntityFrameworkCore.Diagnostics;
+using MultiTenancySample.FieldIsolationService.Entities;
+using MultiTenancySample.ServiceDefaults;
+
+namespace MultiTenancySample.FieldIsolationService.EntityFrameworks
+{
+    public class TenantSaveChangesInterceptor(ICurrentTenant currentTenant) : SaveChangesInterceptor
+    {
+        public override InterceptionResult<int> SavingChanges(DbContextEventData eventData, InterceptionResult<int> result)
+        {
+            if (eventData.Context is not null)
+            {
+                MultiTenancyTracking(eventData.Context);
+            }
+
+            return base.SavingChanges(eventData, result);
+        }
+
+        public override ValueTask<InterceptionResult<int>> SavingChangesAsync(DbContextEventData eventData, InterceptionResult<int> result, CancellationToken cancellationToken = default)
+        {
+            if (eventData.Context is not null)
+            {
+                MultiTenancyTracking(eventData.Context);
+            }
+
+            return base.SavingChangesAsync(eventData, result, cancellationToken);
+        }
+
+        private void MultiTenancyTracking(DbContext dbContext)
+        {
+            IEnumerable<EntityEntry<IMultiTenant>> multiTenancyEntries = dbContext.ChangeTracker.Entries<IMultiTenant>().Where(entry => entry.State == EntityState.Added || entry.State == EntityState.Modified);
+
+            multiTenancyEntries?.ToList().ForEach(entityEntry =>
+            {
+                entityEntry.Entity.TenantId ??= currentTenant.TenantId;
+            });
+        }
+    }
+}