fix: Make database-first scaffolding round-trip produce working migrations

.gitignore

@@ -432,6 +432,7 @@ samples/Eftdb.Samples.Shared/Migrations/
 
 # Ignore all scaffolded models and the DbContext from the DbFirst project
 samples/Eftdb.Samples.DatabaseFirst/**/*.cs
+!samples/Eftdb.Samples.DatabaseFirst/Program.cs
 
 # AI - personal overrides only
 .claude/settings.local.json

README.md

@@ -1,6 +1,5 @@
 # CmdScale.EntityFrameworkCore.TimescaleDB
 
-![CmdScale Project](https://github.com/cmdscale/.github/raw/main/profile/assets/CmdShield.svg)
 [![Test Workflow](https://github.com/cmdscale/CmdScale.EntityFrameworkCore.TimescaleDB/actions/workflows/run-tests.yml/badge.svg)](https://github.com/cmdscale/CmdScale.EntityFrameworkCore.TimescaleDB/actions/workflows/run-tests.yml)
 [![NuGet downloads](https://img.shields.io/nuget/dt/CmdScale.EntityFrameworkCore.TimescaleDB?logo=nuget&label=Downloads)](https://www.nuget.org/packages/CmdScale.EntityFrameworkCore.TimescaleDB)
 [![codecov](https://codecov.io/gh/cmdscale/CmdScale.EntityFrameworkCore.TimescaleDB/graph/badge.svg?token=YP3YCJLQ41)](https://codecov.io/gh/cmdscale/CmdScale.EntityFrameworkCore.TimescaleDB)
@@ -42,6 +41,10 @@ Seamlessly define and manage **TimescaleDB hypertables** using standard EF Core
 
 Take full control over how your hypertable data is organized on disk with **TimescaleDB's** reorder policies. By defining a reorder policy, you can automatically re-sort chunks of data by a specified index, significantly improving the performance of queries that scan large time ranges or specific index values.
 
+### Retention Policies
+
+Automatically drop old chunks from hypertables and continuous aggregates so storage stays bounded as your time-series data grows.
+
 ### Continuous Aggregates
 
 Create and manage **TimescaleDB continuous aggregates** — automatically refreshed materialized views that pre-compute aggregate data for faster queries. Define time-bucketed aggregations using a type-safe Fluent API or Data Annotations.
@@ -52,6 +55,16 @@ Create and manage **TimescaleDB continuous aggregates** — automatically refres
 - **Filtering**: Apply WHERE clauses to filter source data.
 - **Refresh Policies**: Configure automatic refresh with customizable time windows, schedule intervals, and batching options.
 
+### Query Functions
+
+Call TimescaleDB SQL functions directly from LINQ via `EF.Functions.*` extensions. Each entry below translates to its TimescaleDB equivalent at query time:
+
+| `EF.Functions.*` | TimescaleDB | Purpose                                           |
+| ---------------- | ----------- | ------------------------------------------------- |
+| `TimeBucket`     | `time_bucket()` | Group rows into fixed-width time intervals.   |
+
+> More TimescaleDB function support coming soon.
+
 ---
 
 ## 📦 NuGet Packages

benchmarks/Eftdb.Benchmarks/Eftdb.Benchmarks.csproj

@@ -16,7 +16,7 @@
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.15.8" />
     <PackageReference Include="Testcontainers.PostgreSql" Version="4.11.0" />
-    <PackageReference Include="Z.EntityFramework.Extensions.EFCore" Version="10.105.3" />
+    <PackageReference Include="Z.EntityFramework.Extensions.EFCore" Version="10.105.4" />
   </ItemGroup>
 
   <ItemGroup>

samples/Eftdb.Samples.CodeFirst/Eftdb.Samples.CodeFirst.csproj

@@ -11,7 +11,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="EFCore.NamingConventions" Version="10.0.1" />
-		<PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.5" />
+		<PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.7" />
 	</ItemGroup>
 
 	<ItemGroup>

samples/Eftdb.Samples.DatabaseFirst/Eftdb.Samples.DatabaseFirst.csproj

@@ -6,6 +6,7 @@
 
 	<PropertyGroup>
 		<TargetFramework>net10.0</TargetFramework>
+		<OutputType>Exe</OutputType>
 		<ImplicitUsings>enable</ImplicitUsings>
 		<Nullable>enable</Nullable>
 		<AssemblyName>CmdScale.EntityFrameworkCore.TimescaleDB.Samples.DatabaseFirst</AssemblyName>

samples/Eftdb.Samples.DatabaseFirst/Program.cs

@@ -0,0 +1 @@
+return 0;

src/Eftdb.Design/Eftdb.Design.csproj

@@ -24,7 +24,7 @@
 		<PackageTags>timescaledb;timescale;efcore;ef-core;entityframeworkcore;postgresql;postgres;time-series;timeseries;data;database;efcore-provider;provider;design;migrations;scaffolding;codegen;cli;tools</PackageTags>
 	</PropertyGroup>
 	<ItemGroup>
-		<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.5" />
+		<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.7" />
 	</ItemGroup>
 	<ItemGroup>
 		<None Include="..\..\assets\cmd-nuget-logo.jpg">

src/Eftdb.Design/Scaffolding/ContinuousAggregateAnnotationApplier.cs

@@ -27,9 +27,11 @@ public void ApplyAnnotations(DatabaseTable table, object featureInfo)
                 table[ContinuousAggregateAnnotations.ChunkInterval] = info.ChunkInterval;
             }
 
-            // Store the view definition for reference (custom annotation)
-            // This will help users understand the structure when scaffolding
-            table["TimescaleDB:ViewDefinition"] = info.ViewDefinition;
+            // Capture the catalog's view body so the runtime extractor + generator can
+            // round-trip CREATE MATERIALIZED VIEW without needing structured time_bucket /
+            // aggregate / group_by annotations (which the scaffolder cannot reliably
+            // recover from the catalog).
+            table[ContinuousAggregateAnnotations.ViewDefinition] = info.ViewDefinition;
         }
     }
 }

src/Eftdb.Design/Scaffolding/HypertableScaffoldingExtractor.cs

@@ -77,7 +77,7 @@ private static void GetHypertableSettings(
                     column_name,
                     dimension_number,
                     num_partitions,
-                    EXTRACT(EPOCH FROM time_interval) * 1000 AS time_interval_microseconds,
+                    EXTRACT(EPOCH FROM time_interval) * 1000000 AS time_interval_microseconds,
                     integer_interval
                 FROM timescaledb_information.dimensions
                 ORDER BY hypertable_schema, hypertable_name, dimension_number;";

src/Eftdb.Design/TimescaleDBDesignTimeServices.cs

@@ -15,7 +15,8 @@ public void ConfigureDesignTimeServices(IServiceCollection services)
             new NpgsqlDesignTimeServices().ConfigureDesignTimeServices(services);
 
             services.AddSingleton<ICSharpMigrationOperationGenerator, TimescaleCSharpMigrationOperationGenerator>()
-                    .AddSingleton<IDatabaseModelFactory, TimescaleDatabaseModelFactory>();
+                    .AddSingleton<IDatabaseModelFactory, TimescaleDatabaseModelFactory>()
+                    .AddSingleton<IProviderConfigurationCodeGenerator, TimescaleDbCodeGenerator>();
         }
     }
 }

src/Eftdb.Design/TimescaleDbCodeGenerator.cs

@@ -0,0 +1,32 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Design;
+using Microsoft.EntityFrameworkCore.Scaffolding;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal;
+using System.Reflection;
+
+#pragma warning disable EF1001 // NpgsqlCodeGenerator lives in *.Internal but is public and the documented extension point.
+namespace CmdScale.EntityFrameworkCore.TimescaleDB.Design
+{
+    /// <summary>
+    /// Extends Npgsql's scaffold code generator so the generated <c>OnConfiguring</c> chains
+    /// <c>.UseTimescaleDb()</c> after <c>.UseNpgsql(...)</c>.
+    /// </summary>
+    public class TimescaleDbCodeGenerator(ProviderCodeGeneratorDependencies dependencies)
+        : NpgsqlCodeGenerator(dependencies)
+    {
+        private static readonly MethodInfo UseTimescaleDbMethod =
+            typeof(TimescaleDbContextOptionsBuilderExtensions)
+                .GetMethod(
+                    nameof(TimescaleDbContextOptionsBuilderExtensions.UseTimescaleDb),
+                    [typeof(DbContextOptionsBuilder)])
+            ?? throw new InvalidOperationException(
+                "Could not locate UseTimescaleDb(DbContextOptionsBuilder) via reflection.");
+
+        public override MethodCallCodeFragment GenerateUseProvider(
+            string connectionString,
+            MethodCallCodeFragment? providerOptions)
+            => base.GenerateUseProvider(connectionString, providerOptions)
+                   .Chain(new MethodCallCodeFragment(UseTimescaleDbMethod));
+    }
+}
+#pragma warning restore EF1001

src/Eftdb/Configuration/ContinuousAggregate/ContinuousAggregateAnnotations.cs

@@ -20,5 +20,14 @@ public static class ContinuousAggregateAnnotations
         public const string AggregateFunctions = "TimescaleDB:AggregateFunctions";
         public const string WhereClause = "TimescaleDB:WhereClause";
         public const string GroupByColumns = "TimescaleDB:GroupByColumns";
+
+        /// <summary>
+        /// Raw SQL view body captured by the design-time scaffolder. When present, the
+        /// runtime extractor and generator use it verbatim as the SELECT clause of
+        /// CREATE MATERIALIZED VIEW instead of synthesising from structured fields. The
+        /// scaffolder cannot reliably reverse-engineer time_bucket / aggregate / group_by
+        /// structure from the catalog, so this raw form is the round-trip fallback.
+        /// </summary>
+        public const string ViewDefinition = "TimescaleDB:ViewDefinition";
     }
 }

src/Eftdb/Generators/ContinuousAggregateOperationGenerator.cs

@@ -40,6 +40,25 @@ public List<string> Generate(CreateContinuousAggregateOperation operation)
                 withOptions.Add($"timescaledb.chunk_interval = '{operation.ChunkInterval}'");
             }
 
+            // Raw-SQL path required for scaffolding round-trips
+            if (!string.IsNullOrWhiteSpace(operation.ViewDefinition))
+            {
+                StringBuilder rawSqlBuilder = new();
+                rawSqlBuilder.Append($"CREATE MATERIALIZED VIEW {qualifiedIdentifier}");
+                rawSqlBuilder.AppendLine();
+                rawSqlBuilder.Append($"WITH ({string.Join(", ", withOptions)}) AS");
+                rawSqlBuilder.AppendLine();
+                rawSqlBuilder.Append(operation.ViewDefinition!.Trim().TrimEnd(';').Replace("\"", quoteString));
+                if (operation.WithNoData)
+                {
+                    rawSqlBuilder.AppendLine();
+                    rawSqlBuilder.Append("WITH NO DATA");
+                }
+                rawSqlBuilder.Append(';');
+                statements.Add(rawSqlBuilder.ToString());
+                return statements;
+            }
+
             // Build the SELECT list
             List<string> selectList = [];
 

src/Eftdb/Internals/ColumnNameResolver.cs

@@ -0,0 +1,49 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+namespace CmdScale.EntityFrameworkCore.TimescaleDB.Internals
+{
+    /// <summary>
+    /// Resolves a name to a database column name on a given entity, accepting either
+    /// the CLR property name (canonical for code-first usage including EFCore.NamingConventions)
+    /// or the database column name itself (form emitted by the design-time scaffolder).
+    /// </summary>
+    internal static class ColumnNameResolver
+    {
+        /// <summary>
+        /// Returns the database column name for <paramref name="nameOrColumn"/> on
+        /// <paramref name="entityType"/>, or <c>null</c> if no matching property exists.
+        /// </summary>
+        /// <remarks>
+        /// Resolution is two-step: first by CLR property name (so naming-convention plugins
+        /// translate to the actual store column), then by reverse lookup against each
+        /// property's resolved column name (so a value already in column-name form is
+        /// recognised). Both steps consult <c>GetColumnName(StoreObjectIdentifier)</c>,
+        /// which honours all registered conventions.
+        /// </remarks>
+        public static string? Resolve(IEntityType entityType, string? nameOrColumn, StoreObjectIdentifier storeIdentifier)
+        {
+            if (string.IsNullOrWhiteSpace(nameOrColumn))
+            {
+                return null;
+            }
+
+            string? viaClrName = entityType.FindProperty(nameOrColumn)?.GetColumnName(storeIdentifier);
+            if (!string.IsNullOrWhiteSpace(viaClrName))
+            {
+                return viaClrName;
+            }
+
+            foreach (IProperty property in entityType.GetProperties())
+            {
+                string? columnName = property.GetColumnName(storeIdentifier);
+                if (string.Equals(columnName, nameOrColumn, StringComparison.Ordinal))
+                {
+                    return columnName;
+                }
+            }
+
+            return null;
+        }
+    }
+}

src/Eftdb/Internals/Features/ContinuousAggregatePolicies/ContinuousAggregatePolicyModelExtractor.cs

@@ -45,11 +45,16 @@ public static IEnumerable<AddContinuousAggregatePolicyOperation> GetContinuousAg
                 if (!string.IsNullOrWhiteSpace(parentModelName))
                 {
                     parentEntityType = relationalModel.Model.GetEntityTypes()
-                        .FirstOrDefault(e => e.ClrType?.Name == parentModelName || e.ShortName() == parentModelName);
+                        .FirstOrDefault(e =>
+                            e.ClrType?.Name == parentModelName
+                            || e.ShortName() == parentModelName
+                            || e.GetTableName() == parentModelName);
                 }
 
-                // Use parent table's schema for the continuous aggregate (matching ContinuousAggregateModelExtractor behavior)
-                string schema = parentEntityType?.GetSchema() ?? entityType.GetSchema() ?? DefaultValues.DefaultSchema;
+                string schema = entityType.GetViewSchema()
+                    ?? entityType.GetSchema()
+                    ?? parentEntityType?.GetSchema()
+                    ?? DefaultValues.DefaultSchema;
 
                 // Extract policy configuration from annotations
                 string? startOffset = entityType.FindAnnotation(ContinuousAggregatePolicyAnnotations.StartOffset)?.Value as string;

src/Eftdb/Internals/Features/ContinuousAggregates/ContinuousAggregateDiffer.cs

@@ -65,7 +65,8 @@ public IReadOnlyList<MigrationOperation> GetDifferences(IRelationalModel? source
                     x.Target.WithNoData != x.Source.WithNoData ||
                     !AreAggregateFunctionsEqual(x.Target.AggregateFunctions, x.Source.AggregateFunctions) ||
                     !AreGroupByColumnsEqual(x.Target.GroupByColumns, x.Source.GroupByColumns) ||
-                    x.Target.WhereClause != x.Source.WhereClause
+                    x.Target.WhereClause != x.Source.WhereClause ||
+                    x.Target.ViewDefinition != x.Source.ViewDefinition
                 );
 
             foreach (var aggregate in structurallyChangedAggregates)

src/Eftdb/Internals/Features/ContinuousAggregates/ContinuousAggregateModelExtractor.cs

@@ -31,9 +31,12 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                     continue;
                 }
 
-                // Find the parent entity type to get its table name
+                // Find the parent entity type
                 IEntityType? parentEntityType = relationalModel.Model.GetEntityTypes()
-                    .FirstOrDefault(e => e.ClrType?.Name == parentModelName || e.ShortName() == parentModelName);
+                    .FirstOrDefault(e =>
+                        e.ClrType?.Name == parentModelName
+                        || e.ShortName() == parentModelName
+                        || e.GetTableName() == parentModelName);
                 if (parentEntityType == null)
                 {
                     continue;
@@ -46,14 +49,13 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                 }
 
                 // Get time bucket configuration
-                string? timeBucketWidth = entityType.FindAnnotation(ContinuousAggregateAnnotations.TimeBucketWidth)?.Value as string;
-                if (string.IsNullOrWhiteSpace(timeBucketWidth))
-                {
-                    continue;
-                }
+                string? viewDefinition = entityType.FindAnnotation(ContinuousAggregateAnnotations.ViewDefinition)?.Value as string;
+                bool useRawDefinition = !string.IsNullOrWhiteSpace(viewDefinition);
 
+                // Get time bucket configuration
+                string? timeBucketWidth = entityType.FindAnnotation(ContinuousAggregateAnnotations.TimeBucketWidth)?.Value as string;
                 string? timeBucketSourceColumnModelName = entityType.FindAnnotation(ContinuousAggregateAnnotations.TimeBucketSourceColumn)?.Value as string;
-                if (string.IsNullOrWhiteSpace(timeBucketSourceColumnModelName))
+                if (!useRawDefinition && (string.IsNullOrWhiteSpace(timeBucketWidth) || string.IsNullOrWhiteSpace(timeBucketSourceColumnModelName)))
                 {
                     continue;
                 }
@@ -62,11 +64,14 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                 StoreObjectIdentifier parentStoreIdentifier = StoreObjectIdentifier.Table(parentTableName, parentEntityType.GetSchema());
 
                 string? viewName = entityType.GetViewName() ?? materializedViewName;
-                StoreObjectIdentifier aggregateStoreIdentifier = StoreObjectIdentifier.View(viewName, entityType.GetSchema());
-
-                // Resolve time bucket source column to database column name
-                string? timeBucketSourceColumn = parentEntityType.FindProperty(timeBucketSourceColumnModelName)?.GetColumnName(parentStoreIdentifier);
-                if (string.IsNullOrWhiteSpace(timeBucketSourceColumn))
+                StoreObjectIdentifier aggregateStoreIdentifier = StoreObjectIdentifier.View(viewName, entityType.GetViewSchema() ?? entityType.GetSchema());
+
+                // Resolve time bucket source column to database column name. Skipped on
+                // the raw-definition path because the structured field is unused.
+                string? timeBucketSourceColumn = useRawDefinition
+                    ? null
+                    : ColumnNameResolver.Resolve(parentEntityType, timeBucketSourceColumnModelName!, parentStoreIdentifier);
+                if (!useRawDefinition && string.IsNullOrWhiteSpace(timeBucketSourceColumn))
                 {
                     continue;
                 }
@@ -98,7 +103,7 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                         string sourceColumnModelName = parts[2];
 
                         // Resolve source column name from parent entity
-                        string? sourceColumnDbName = parentEntityType.FindProperty(sourceColumnModelName)?.GetColumnName(parentStoreIdentifier);
+                        string? sourceColumnDbName = ColumnNameResolver.Resolve(parentEntityType, sourceColumnModelName, parentStoreIdentifier);
                         if (string.IsNullOrWhiteSpace(sourceColumnDbName))
                         {
                             // Skip if source column not found
@@ -141,8 +146,12 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                     }
                 }
 
-                // Use parent table's schema for the continuous aggregate
-                string schema = parentEntityType.GetSchema() ?? entityType.GetSchema() ?? DefaultValues.DefaultSchema;
+                // Schema resolution: prefer the CA's own view schema (set by .ToView(...)
+                // or by the scaffolder), fall back to the parent's schema, finally default.
+                string schema = entityType.GetViewSchema()
+                    ?? entityType.GetSchema()
+                    ?? parentEntityType.GetSchema()
+                    ?? DefaultValues.DefaultSchema;
 
                 yield return new CreateContinuousAggregateOperation
                 {
@@ -153,12 +162,13 @@ public static IEnumerable<CreateContinuousAggregateOperation> GetContinuousAggre
                     WithNoData = withNoData,
                     CreateGroupIndexes = createGroupIndexes,
                     MaterializedOnly = materializedOnly,
-                    TimeBucketWidth = timeBucketWidth,
-                    TimeBucketSourceColumn = timeBucketSourceColumn,
+                    TimeBucketWidth = timeBucketWidth ?? string.Empty,
+                    TimeBucketSourceColumn = timeBucketSourceColumn ?? string.Empty,
                     TimeBucketGroupBy = timeBucketGroupBy,
                     AggregateFunctions = aggregateFunctions,
                     GroupByColumns = groupByColumns,
-                    WhereClause = whereClause
+                    WhereClause = whereClause,
+                    ViewDefinition = useRawDefinition ? viewDefinition : null
                 };
             }
         }