Merge pull request #24 from cmdscale/feature/#16_migrate_data_support

Feature/#16 migrate data support

Author: sebastian-ederer

.gitignore

@@ -428,10 +428,10 @@ FodyWeavers.xsd
 *.msp
 
 # Ignore all generated migration files
-CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess/Migrations/
+samples/Eftdb.Samples.Shared/Migrations/
 
 # Ignore all scaffolded models and the DbContext from the DbFirst project
-CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess.DbFirst/
+samples/Eftdb.Samples.DatabaseFirst/**/*.cs
 
 # AI
 CLAUDE.md

README.md

@@ -24,6 +24,7 @@ Seamlessly define and manage **TimescaleDB hypertables** using standard EF Core
 - **Time Partitioning**: Easily specify the primary time column and set the `chunk_time_interval`.
 - **Space Partitioning**: Add additional dimensions for hash or range partitioning to further optimize queries.
 - **Chunk Time Interval**: Configure chunk intervals to balance performance and storage efficiency.
+- **Data Migration**: Control whether existing data should be migrated when converting a regular table to a hypertable using `migrate_data`.
 - **Compression & Chunk Skipping**: Enable TimescaleDB's native compression and configure chunk skipping to improve query performance.
 
 ### Reorder Policies
@@ -97,7 +98,9 @@ public class WeatherDataConfiguration : IEntityTypeConfiguration<WeatherData>
                // Optional: Enable chunk skipping for faster queries on this column.
                .WithChunkSkipping(x => x.Time)
                // Optional: Set the chunk interval. Can be a string ("7 days") or long (microseconds).
-               .WithChunkTimeInterval("86400000");
+               .WithChunkTimeInterval("86400000")
+               // Optional: Migrate existing data when converting to hypertable (defaults to false).
+               .WithMigrateData(true);
     }
 }
 ```
@@ -108,7 +111,10 @@ public class WeatherDataConfiguration : IEntityTypeConfiguration<WeatherData>
 For simpler configurations, you can use the [Hypertable] attribute directly on your model class.
 
 ```csharp
-[Hypertable(nameof(Time), ChunkSkipColumns = new[] { "Time" }, ChunkTimeInterval = "86400000")]
+[Hypertable(nameof(Time),
+    ChunkSkipColumns = new[] { "Time" },
+    ChunkTimeInterval = "86400000",
+    MigrateData = true)]
 [PrimaryKey(nameof(Id), nameof(Time))]
 public class DeviceReading
 {

samples/Eftdb.Samples.CodeFirst/README.md

@@ -1,69 +1,78 @@
-# EF Core Code-First Example with TimescaleDB
+# EF Core Code-First Example with TimescaleDB
 
 This project demonstrates how to use the **Code-First** approach with [TimescaleDB](https://www.timescale.com/) using the `CmdScale.EntityFrameworkCore.TimescaleDB` package.
 
 ---
 
-## 🚀 Migrations and Database Management
+## Migrations and Database Management
 
 Use the following commands to manage your EF Core migrations and database updates.
 
-### 📌 Add a new migration
+> **Note:** Run all commands from the repository root directory.
+
+### Add a new migration
 
 ```bash
-dotnet ef migrations add --project CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess --startup-project CmdScale.EntityFrameworkCore.TimescaleDB.Example <MigrationName>
+dotnet ef migrations add <MigrationName> --project samples/Eftdb.Samples.Shared --startup-project samples/Eftdb.Samples.CodeFirst
 ```
 
-### ✅ Apply migrations to the database
+### Apply migrations to the database
 
 ```bash
-dotnet ef database update --project CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess --startup-project CmdScale.EntityFrameworkCore.TimescaleDB.Example
+dotnet ef database update --project samples/Eftdb.Samples.Shared --startup-project samples/Eftdb.Samples.CodeFirst
 ```
 
-### ❌ Remove last migration (if not applied to the database, yet)
-```
- dotnet ef migrations remove --project CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess --startup-project CmdScale.EntityFrameworkCore.TimescaleDB.Example
+### Remove last migration (if not applied to the database yet)
+
+```bash
+dotnet ef migrations remove --project samples/Eftdb.Samples.Shared --startup-project samples/Eftdb.Samples.CodeFirst
 ```
 
-### 🧹 Reset all migrations (rollback to initial state)
+### Reset all migrations (rollback to initial state)
 
 ```bash
-dotnet ef database update 0 --project CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess --startup-project CmdScale.EntityFrameworkCore.TimescaleDB.Example
+dotnet ef database update 0 --project samples/Eftdb.Samples.Shared --startup-project samples/Eftdb.Samples.CodeFirst
 ```
 
 ---
 
-## 📁 Project Structure
+## Project Structure
 
 ```text
-CmdScale.EntityFrameworkCore.TimescaleDB.Example/
-│
-├── CmdScale.EntityFrameworkCore.TimescaleDB.Example/            # Startup project
-├── CmdScale.EntityFrameworkCore.TimescaleDB.Example.DataAccess/ # Contains DbContext and migrations
-└── docker-compose.yml                                           # Sets up TimescaleDB container (in Solution Items)
+samples/
+├── Eftdb.Samples.CodeFirst/   # Startup project (contains Program.cs and design-time services)
+├── Eftdb.Samples.Shared/      # Contains DbContext, entities, and migrations
+└── Eftdb.Samples.DatabaseFirst/ # Database-first scaffolding example
 ```
 
 ---
 
-## 🐳 Docker
-- This project assumes you have an existing TimescaleDB-compatible PostgreSQL database.
-- A `docker-compose.yml` file is included in the **Solution Items** folder to spin up a TimescaleDB container for local development and testing.
+## Docker
+
+This project assumes you have an existing TimescaleDB-compatible PostgreSQL database. A `docker-compose.yml` file is included in the repository root to spin up a TimescaleDB container for local development and testing.
 
-  To start the container, run:
+To start the container, run from the repository root:
 
-  ```bash
-  docker-compose up -d
-  ```
+```bash
+docker-compose up -d
+```
+
+To stop and reset the database:
+
+```bash
+docker-compose down -v
+```
 
-- Connection string settings should match the configuration in your `docker-compose.yml`.
+Connection string settings should match the configuration in your `docker-compose.yml`.
 
 ---
 
-## 🧠 Notes
-- Depending on if you're using project- or package-references you might to (un)comment adding the services in `TimescaleDBDesignTimeService.cs`
+## Notes
 
+- Depending on if you're using project- or package-references you might need to (un)comment adding the services in `TimescaleDBDesignTimeService.cs`
+- The `Eftdb.Samples.Shared` project contains the `TimescaleContext` and entity models shared between samples
 
-## 📚 Resources
+## Resources
 
 - [Entity Framework Core Documentation](https://learn.microsoft.com/en-us/ef/core/)
 - [TimescaleDB Documentation](https://docs.timescale.com/)

src/Eftdb.Design/TimescaleCSharpMigrationOperationGenerator.cs

@@ -17,7 +17,7 @@ protected override void Generate(MigrationOperation operation, IndentedStringBui
             ReorderPolicyOperationGenerator? reorderPolicyOperationGenerator = null;
             ContinuousAggregateOperationGenerator? continuousAggregateOperationGenerator = null;
 
-            List<string> statements = [];
+            List<string> statements;
             bool suppressTransaction = false;
 
             switch (operation)
@@ -60,7 +60,14 @@ protected override void Generate(MigrationOperation operation, IndentedStringBui
 
                 default:
                     base.Generate(operation, builder);
-                    break;
+                    return;
+            }
+
+            // Guard: if no statements were generated, output a no-op SQL comment to maintain valid C# syntax.
+            if (statements.Count == 0)
+            {
+                builder.Append(".Sql(@\"-- No SQL generated for this operation\")");
+                return;
             }
 
             SqlBuilderHelper.BuildQueryString(statements, builder, suppressTransaction);

src/Eftdb/Configuration/Hypertable/HypertableAnnotations.cs

@@ -8,6 +8,7 @@ public static class HypertableAnnotations
         public const string IsHypertable = "TimescaleDB:IsHypertable";
         public const string HypertableTimeColumn = "TimescaleDB:TimeColumnName";
         public const string EnableCompression = "TimescaleDB:EnableCompression";
+        public const string MigrateData = "TimescaleDB:MigrateData";
         public const string ChunkTimeInterval = "TimescaleDB:ChunkTimeInterval";
         public const string ChunkSkipColumns = "TimescaleDB:ChunkSkipColumns";
         public const string AdditionalDimensions = "TimescaleDB:AdditionalDimensions";

src/Eftdb/Configuration/Hypertable/HypertableAttribute.cs

@@ -10,10 +10,15 @@ public sealed class HypertableAttribute : Attribute
         public string TimeColumnName { get; } = string.Empty;
 
         /// <summary>
-        /// 
+        /// Specifies whether compression is enabled on the hypertable.
         /// </summary>
         public bool EnableCompression { get; set; } = false;
 
+        /// <summary>
+        /// Specifies whether existing data should be migrated when converting a table to a hypertable.
+        /// </summary>
+        public bool MigrateData { get; set; } = false;
+
         /// <summary>
         /// Defines the duration of time covered by each chunk in a hypertable.
         /// </summary>

src/Eftdb/Configuration/Hypertable/HypertableConvention.cs

@@ -37,6 +37,11 @@ public void ProcessEntityTypeAdded(IConventionEntityTypeBuilder entityTypeBuilde
                     entityTypeBuilder.HasAnnotation(HypertableAnnotations.EnableCompression, true);
                 }
 
+                if (attribute.MigrateData == true)
+                {
+                    entityTypeBuilder.HasAnnotation(HypertableAnnotations.MigrateData, true);
+                }
+
                 if (attribute.ChunkSkipColumns != null && attribute.ChunkSkipColumns.Length > 0)
                 {
                     /// Chunk skipping requires compression to be enabled

src/Eftdb/Configuration/Hypertable/HypertableTypeBuilder.cs

@@ -128,6 +128,25 @@ public static EntityTypeBuilder<TEntity> EnableCompression<TEntity>(
             return entityTypeBuilder;
         }
 
+        /// <summary>
+        /// Specifies whether existing data should be migrated when converting a table to a hypertable.
+        /// </summary>
+        /// <remarks>
+        /// When converting an existing table to a hypertable, this parameter controls whether existing data
+        /// is migrated into chunks. If set to false, only new data will be stored in chunks.
+        /// Defaults to <c>false</c> to match TimescaleDB's default behavior.
+        /// </remarks>
+        /// <typeparam name="TEntity">The entity type being configured.</typeparam>
+        /// <param name="entityTypeBuilder">The builder for the entity type.</param>
+        /// <param name="migrateData">A boolean indicating whether to migrate existing data. Defaults to <c>true</c>.</param>
+        public static EntityTypeBuilder<TEntity> WithMigrateData<TEntity>(
+            this EntityTypeBuilder<TEntity> entityTypeBuilder,
+            bool migrateData = true) where TEntity : class
+        {
+            entityTypeBuilder.HasAnnotation(HypertableAnnotations.MigrateData, migrateData);
+            return entityTypeBuilder;
+        }
+
         /// <summary>
         /// Extracts the property name from a member access lambda expression.
         /// </summary>

src/Eftdb/Generators/HypertableOperationGenerator.cs

@@ -24,9 +24,11 @@ public List<string> Generate(CreateHypertableOperation operation)
             string qualifiedTableName = sqlHelper.Regclass(operation.TableName, operation.Schema);
             string qualifiedIdentifier = sqlHelper.QualifiedIdentifier(operation.TableName, operation.Schema);
 
+            string migrateDataParam = operation.MigrateData ? ", migrate_data => true" : "";
+
             List<string> statements =
             [
-                $"SELECT create_hypertable({qualifiedTableName}, '{operation.TimeColumnName}');"
+                $"SELECT create_hypertable({qualifiedTableName}, '{operation.TimeColumnName}'{migrateDataParam});"
             ];
 
             // ChunkTimeInterval

src/Eftdb/Internals/Features/Hypertables/HypertableModelExtractor.cs

@@ -76,6 +76,7 @@ public static IEnumerable<CreateHypertableOperation> GetHypertables(IRelationalM
 
                 string chunkTimeInterval = entityType.FindAnnotation(HypertableAnnotations.ChunkTimeInterval)?.Value as string ?? DefaultValues.ChunkTimeInterval;
                 bool enableCompression = entityType.FindAnnotation(HypertableAnnotations.EnableCompression)?.Value as bool? ?? false;
+                bool migrateData = entityType.FindAnnotation(HypertableAnnotations.MigrateData)?.Value as bool? ?? false;
 
                 yield return new CreateHypertableOperation
                 {
@@ -84,6 +85,7 @@ public static IEnumerable<CreateHypertableOperation> GetHypertables(IRelationalM
                     TimeColumnName = timeColumnName,
                     ChunkTimeInterval = chunkTimeInterval ?? DefaultValues.ChunkTimeInterval,
                     EnableCompression = enableCompression,
+                    MigrateData = migrateData,
                     ChunkSkipColumns = chunkSkipColumns,
                     AdditionalDimensions = additionalDimensions
                 };