Remove relational modeling, clean up concurrency page

Closes #1669

.openpublishing.redirection.json

@@ -309,6 +309,16 @@
             "source_path": "entity-framework/core/modeling/relational/inheritance.md",
             "redirect_url": "/ef/core/modeling/inheritance",
             "redirect_document_id": false
+        },
+        {
+            "source_path": "entity-framework/core/modeling/relational/",
+            "redirect_url": "/ef/core/modeling/",
+            "redirect_document_id": false
+        },
+        {
+            "source_path": "entity-framework/core/modeling/relational/index",
+            "redirect_url": "/ef/core/modeling/",
+            "redirect_document_id": false
         }
     ]
 }

entity-framework/core/modeling/concurrency.md

@@ -12,40 +12,30 @@ uid: core/modeling/concurrency
 
 Properties configured as concurrency tokens are used to implement optimistic concurrency control.
 
-## Conventions
+## Configuration
 
-By convention, properties are never configured as concurrency tokens.
+### [Data Annotations](#tab/data-annotations)
 
-## Data Annotations
+[!code-csharp[Main](../../../samples/core/Modeling/DataAnnotations/Concurrency.cs?name=Concurrency&highlight=5)]
 
-You can use the Data Annotations to configure a property as a concurrency token.
+### [Fluent API](#tab/fluent-api)
 
-[!code-csharp[Main](../../../samples/core/Modeling/DataAnnotations/Concurrency.cs#ConfigureConcurrencyAnnotations)]
+[!code-csharp[Main](../../../samples/core/Modeling/FluentAPI/Concurrency.cs?name=Concurrency&highlight=5)]
 
-## Fluent API
+***
 
-You can use the Fluent API to configure a property as a concurrency token.
+## Timestamp/rowversion
 
-[!code-csharp[Main](../../../samples/core/Modeling/FluentAPI/Concurrency.cs#ConfigureConcurrencyFluent)]
+A timestamp/rowversion is a property for which a new value is automatically generated by the database every time a row is inserted or updated. The property is also treated as a concurrency token, ensuring that you get an exception if a row you are updating has changed since you queried it. The precise details depend on the database provider being used; for SQL Server, a *byte[]* property is usually used, which will be set up as a *ROWVERSION* column in the database.
 
-## Timestamp/row version
+You can configure a property to be a timestamp/rowversion as follows:
 
-A timestamp is a property where a new value is generated by the database every time a row is inserted or updated. The property is also treated as a concurrency token. This ensures you will get an exception if anyone else has modified a row that you are trying to update since you queried for the data.
+### [Data Annotations](#tab/data-annotations)
 
-How this is achieved is up to the database provider being used. For SQL Server, timestamp is usually used on a *byte[]* property, which will be setup as a *ROWVERSION* column in the database.
+[!code-csharp[Main](../../../samples/core/Modeling/DataAnnotations/Timestamp.cs?name=Timestamp&highlight=9,17)]
 
-### Conventions
+### [Fluent API](#tab/fluent-api)
 
-By convention, properties are never configured as timestamps.
+[!code-csharp[Main](../../../samples/core/Modeling/FluentAPI/Timestamp.cs?name=Timestamp&highlight=7)]
 
-### Data Annotations
-
-You can use Data Annotations to configure a property as a timestamp.
-
-[!code-csharp[Main](../../../samples/core/Modeling/DataAnnotations/Timestamp.cs#ConfigureTimestampAnnotations)]
-
-### Fluent API
-
-You can use the Fluent API to configure a property as a timestamp.
-
-[!code-csharp[Main](../../../samples/core/Modeling/FluentAPI/Timestamp.cs#ConfigureTimestampFluent)]
+***

entity-framework/toc.yml

@@ -118,10 +118,6 @@
       - name: Spatial Data
         displayName: GIS
         href: core/modeling/spatial.md
-      - name: Relational database modeling
-        items:
-        - name: Overview
-          href: core/modeling/relational/index.md
     - name: Managing Database Schemas
       items:
       - name: Overview

samples/core/Modeling/DataAnnotations/Concurrency.cs

@@ -8,7 +8,7 @@ class MyContext : DbContext
         public DbSet<Person> People { get; set; }
     }
 
-    #region ConfigureConcurrencyAnnotations
+    #region Concurrencty
     public class Person
     {
         public int PersonId { get; set; }

samples/core/Modeling/DataAnnotations/Timestamp.cs

@@ -8,7 +8,7 @@ class MyContext : DbContext
         public DbSet<Blog> Blogs { get; set; }
     }
 
-    #region ConfigureTimestampAnnotations
+    #region Timestamp
     public class Blog
     {
         public int BlogId { get; set; }

samples/core/Modeling/FluentAPI/Concurrency.cs

@@ -2,17 +2,18 @@
 
 namespace EFModeling.FluentAPI.Concurrency
 {
-    #region ConfigureConcurrencyFluent
     class MyContext : DbContext
     {
         public DbSet<Person> People { get; set; }
 
+        #region Concurrency
         protected override void OnModelCreating(ModelBuilder modelBuilder)
         {
             modelBuilder.Entity<Person>()
                 .Property(p => p.LastName)
                 .IsConcurrencyToken();
         }
+        #endregion
     }
 
     public class Person
@@ -21,5 +22,4 @@ public class Person
         public string LastName { get; set; }
         public string FirstName { get; set; }
     }
-    #endregion
 }

samples/core/Modeling/FluentAPI/Timestamp.cs

@@ -2,7 +2,7 @@
 
 namespace EFModeling.FluentAPI.Timestamp
 {
-    #region ConfigureTimestampFluent
+    #region Timestamp
     class MyContext : DbContext
     {
         public DbSet<Blog> Blogs { get; set; }