feat: support auto-generated primary keys with IDENTITY columns (#503)

* feat: support auto-generated primary keys with IDENTITY columns

Adds support for auto-generated primary keys using IDENTITY columns.
Standard primary key columns in Entity Framework are translated to
`GENERATED BY DEFAULT AS IDENTITY (BIT_REVERSED_POSITIVE)` for Spanner.

The methods added in SpannerModelBuilderExtensions can be used to
configure the strategy for generating primary keys:

`SpannerModelBuilderExtensions.DisableIdentityColumns()` disables the use
of IDENTITY for primary keys.

`SpannerModelBuilderExtensions.UseAutoIncrement()` configures the Entity
Framework provider to generate `AUTO_INCREMENT` columns instead of a
`GENERATED BY DEFAULT` clause. This can only be used if the database has
a `default_sequence_kind` option set.

The `SpannerModelExtensions.SetIdentityOptions` method can be used to
manually configure the generation strategy. This can be used to set a
custom sequence kind.

* chore: cleanup

Author: olavloite

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/MigrationTests/MigrationModels/AllColType.cs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-using Google.Cloud.EntityFrameworkCore.Spanner.Storage;
 using Google.Cloud.Spanner.V1;
 using System;
 using System.Collections.Generic;
@@ -23,7 +22,7 @@ namespace Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests
 {
     public partial class AllColType
     {
-        public int Id { get; set; }
+        public long Id { get; set; }
         public short? ColShort { get; set; }
         public int? ColInt { get; set; }
         public long? ColLong { get; set; }

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/MigrationTests/Migrations/20210830082803_Initial.cs

@@ -29,7 +29,7 @@ protected override void Up(MigrationBuilder migrationBuilder)
                 name: "AllColTypes",
                 columns: table => new
                 {
-                    Id = table.Column<int>(nullable: false),
+                    Id = table.Column<int>(nullable: false).Annotation(SpannerAnnotationNames.Identity, SpannerIdentityOptionsData.Default),
                     ColShort = table.Column<short>(nullable: true),
                     ColInt = table.Column<int>(nullable: true),
                     ColLong = table.Column<long>(nullable: true),

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/MigrationTests/SpannerMigrationTest.cs

@@ -90,15 +90,15 @@ public async Task CanInsertAndUpdateNullValues()
         {
             using var context = new TestMigrationDbContext(_fixture.DatabaseName);
 
-            context.AllColTypes.Add(new AllColType
+            var entry = context.AllColTypes.Add(new AllColType
             {
-                Id = 1,
                 ColString = "Test String"
             });
 
             var rowCount = await context.SaveChangesAsync();
             Assert.Equal(1, rowCount);
-            var row = await context.AllColTypes.FindAsync(1);
+            Assert.True(entry.Entity.Id > 0L, $"entry.Entity.Id > 0L, but was {entry.Entity.Id}");
+            var row = await context.AllColTypes.FindAsync(entry.Entity.Id);
             Assert.NotNull(row);
             Assert.Null(row.ColTimestamp);
             Assert.Null(row.ColShort);
@@ -115,7 +115,7 @@ public async Task CanInsertAndUpdateNullValues()
             await context.SaveChangesAsync();
 
             // Retrieve updated row from database
-            row = await context.AllColTypes.FindAsync(1);
+            row = await context.AllColTypes.FindAsync(row.Id);
             Assert.NotNull(row);
             Assert.NotNull(row.ColBool);
             Assert.NotNull(row.ColBoolArray);
@@ -135,7 +135,7 @@ public async Task CanInsertAndUpdateNullValues()
             await context.SaveChangesAsync();
 
             // Retrieve updated row from database
-            row = await context.AllColTypes.FindAsync(1);
+            row = await context.AllColTypes.FindAsync(row.Id);
             Assert.NotNull(row);
             Assert.Null(row.ColBool);
             Assert.Null(row.ColBoolArray);
@@ -202,7 +202,7 @@ public async Task CanInsertAndUpdateRowWithAllDataTypes()
             // Get inserted Rows from database.
             using (var context = new TestMigrationDbContext(_fixture.DatabaseName))
             {
-                var row = await context.AllColTypes.FindAsync(10);
+                var row = await context.AllColTypes.FindAsync(10L);
                 Assert.NotNull(row);
                 Assert.Equal(10, row.Id);
                 Assert.True(row.ColBool);
@@ -303,7 +303,7 @@ public async Task CanInsertAndUpdateRowWithAllDataTypes()
             // Retrieve Updated Rows
             using (var context = new TestMigrationDbContext(_fixture.DatabaseName))
             {
-                var row = await context.AllColTypes.FindAsync(10);
+                var row = await context.AllColTypes.FindAsync(10L);
                 Assert.NotNull(row);
                 Assert.False(row.ColBool);
                 Assert.Equal(new [] { false, true, false }, row.ColBoolArray);
@@ -518,7 +518,7 @@ public async Task CanInsertAndDeleteInterleaveOnDeleteCascade()
                 };
                 context.Articles.Add(article);
                 var rowCount = await context.SaveChangesAsync();
-                Assert.Equal(2, rowCount);
+                Assert.Equal(1, rowCount);
             }
 
             using (var context = new TestMigrationDbContext(_fixture.DatabaseName))

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/Model/TicketSales.cs

@@ -1,4 +1,4 @@
-// Copyright 2024 Google LLC
+// Copyright 2025 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/SampleDataModel.sql

@@ -77,6 +77,11 @@ CREATE TABLE Performances (
   CONSTRAINT FK_Performances_Tracks FOREIGN KEY (AlbumId, TrackId) REFERENCES Tracks (AlbumId, TrackId),
 ) PRIMARY KEY (VenueCode, SingerId, StartTime);
 
+CREATE TABLE TicketSales (
+  Id           INT64 NOT NULL GENERATED BY DEFAULT AS IDENTITY (BIT_REVERSED_POSITIVE),
+  CustomerName STRING(MAX),
+) PRIMARY KEY (Id);
+
 CREATE TABLE TableWithAllColumnTypes (
 	ColInt64 INT64 NOT NULL,
 	ColFloat64 FLOAT64,

Google.Cloud.EntityFrameworkCore.Spanner.IntegrationTests/TransactionTests.cs

@@ -313,9 +313,13 @@ public async Task CanExecuteStaleRead()
             }
         }
 
-        [Fact]
+        [SkippableFact]
         public async Task CanUseComputedColumnAndCommitTimestamp()
         {
+            // The emulator does not allow a THEN RETURN clause in combination with
+            // PENDING_COMMIT_TIMESTAMP(), even if the returned columns do not include
+            // the pending commit timestamp column.
+            Skip.If(Environment.GetEnvironmentVariable("SPANNER_EMULATOR_HOST") != null);
             var id1 = _fixture.RandomLong();
             var id2 = _fixture.RandomLong();
 

Google.Cloud.EntityFrameworkCore.Spanner.Samples/SampleModel/Album.cs

@@ -34,7 +34,7 @@ public Album()
         /// See TicketSale for an example of using a server-side generated primary key value using a
         /// bit-reversed sequence.
         /// </summary>
-        public Guid AlbumId { get; set; }
+        public long AlbumId { get; set; }
         public string Title { get; set; }
 
         /// <summary>
@@ -46,7 +46,7 @@ public Album()
         /// <summary>
         /// FOREIGN KEY value referencing a Singer record.
         /// </summary>
-        public Guid SingerId { get; set; }
+        public long SingerId { get; set; }
 
         public virtual Singer Singer { get; set; }
 

Google.Cloud.EntityFrameworkCore.Spanner.Samples/SampleModel/Concert.cs

@@ -33,7 +33,7 @@ public Concert()
         /// them from DATE columns that by default are mapped to <see cref="SpannerDate"/>.
         /// </summary>
         public DateTime StartTime { get; set; }
-        public Guid SingerId { get; set; }
+        public long SingerId { get; set; }
         public string Title { get; set; }
 
         public virtual Singer Singer { get; set; }

Google.Cloud.EntityFrameworkCore.Spanner.Samples/SampleModel/Performance.cs

@@ -20,8 +20,8 @@ public partial class Performance : VersionedEntity
     {
         public string VenueCode { get; set; }
         public DateTime ConcertStartTime { get; set; }
-        public Guid SingerId { get; set; }
-        public Guid AlbumId { get; set; }
+        public long SingerId { get; set; }
+        public long AlbumId { get; set; }
         public long TrackId { get; set; }
         public DateTime? StartTime { get; set; }
         public double? Rating { get; set; }

Google.Cloud.EntityFrameworkCore.Spanner.Samples/SampleModel/SampleDataModel.sql

@@ -14,7 +14,7 @@
 */
 
 CREATE TABLE Singers (
-  SingerId  STRING(36) NOT NULL,
+  SingerId  INT64 NOT NULL GENERATED BY DEFAULT AS IDENTITY (BIT_REVERSED_POSITIVE),
   FirstName STRING(200),
   LastName  STRING(200) NOT NULL,
   BirthDate DATE,
@@ -26,16 +26,16 @@ CREATE TABLE Singers (
 CREATE INDEX Idx_Singers_FullName ON Singers (FullName);
 
 CREATE TABLE Albums (
-  AlbumId     STRING(36) NOT NULL,
+  AlbumId     INT64 NOT NULL GENERATED BY DEFAULT AS IDENTITY (BIT_REVERSED_POSITIVE),
   Title       STRING(100) NOT NULL,
   ReleaseDate DATE,
-  SingerId    STRING(36) NOT NULL,
+  SingerId    INT64 NOT NULL,
   Version     INT64 NOT NULL,
   CONSTRAINT FK_Albums_Singers FOREIGN KEY (SingerId) REFERENCES Singers (SingerId),
 ) PRIMARY KEY (AlbumId);
 
 CREATE TABLE Tracks (
-  AlbumId         STRING(36) NOT NULL,
+  AlbumId         INT64 NOT NULL,
   TrackId         INT64 NOT NULL,
   Title           STRING(200) NOT NULL,
   Duration        NUMERIC,
@@ -58,7 +58,7 @@ CREATE TABLE Venues (
 CREATE TABLE Concerts (
   VenueCode STRING(10) NOT NULL,
   StartTime TIMESTAMP NOT NULL,
-  SingerId  STRING(36) NOT NULL,
+  SingerId  INT64 NOT NULL,
   Title     STRING(200),
   Version   INT64 NOT NULL,
   CONSTRAINT FK_Concerts_Venues FOREIGN KEY (VenueCode) REFERENCES Venues (Code),
@@ -68,8 +68,8 @@ CREATE TABLE Concerts (
 CREATE TABLE Performances (
   VenueCode        STRING(10) NOT NULL,
   ConcertStartTime TIMESTAMP NOT NULL,
-  SingerId         STRING(36) NOT NULL,
-  AlbumId          STRING(36) NOT NULL,
+  SingerId         INT64 NOT NULL,
+  AlbumId          INT64 NOT NULL,
   TrackId          INT64 NOT NULL,
   StartTime        TIMESTAMP,
   Rating           FLOAT64,
@@ -94,7 +94,7 @@ CREATE TABLE TicketSales (
   Seats            ARRAY<STRING(10)> NOT NULL,
   VenueCode        STRING(10) NOT NULL,
   ConcertStartTime TIMESTAMP NOT NULL,
-  SingerId         STRING(36) NOT NULL,
+  SingerId         INT64 NOT NULL,
   Version          INT64 NOT NULL,
   CONSTRAINT FK_TicketSales_Concerts FOREIGN KEY (VenueCode, ConcertStartTime, SingerId) REFERENCES Concerts (VenueCode, StartTime, SingerId),
 ) PRIMARY KEY (Id);