Add overload for including reference types using typed expression

Author: mythz

src/ServiceStack.OrmLite/OrmLiteReadApi.cs

@@ -2,6 +2,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Data;
+using System.Linq;
 using System.Linq.Expressions;
 
 namespace ServiceStack.OrmLite
@@ -667,13 +668,22 @@ public static long LongScalar(this IDbConnection dbConn)
 
         /// <summary>
         /// Returns the first result with all its references loaded, using a primary key id. E.g:
-        /// <para>db.LoadSingleById&lt;Person&gt;(1)</para>
+        /// <para>db.LoadSingleById&lt;Person&gt;(1, include = new[]{ "Address" })</para>
         /// </summary>
         public static T LoadSingleById<T>(this IDbConnection dbConn, object idValue, string[] include = null)
         {
             return dbConn.Exec(dbCmd => dbCmd.LoadSingleById<T>(idValue, include));
         }
 
+        /// <summary>
+        /// Returns the first result with all its references loaded, using a primary key id. E.g:
+        /// <para>db.LoadSingleById&lt;Person&gt;(1, include = x => new{ x.Address })</para>
+        /// </summary>
+        public static T LoadSingleById<T>(this IDbConnection dbConn, object idValue, Func<T,object> include)
+        {
+            return dbConn.Exec(dbCmd => dbCmd.LoadSingleById<T>(idValue, include(typeof(T).CreateInstance<T>()).GetType().AllAnonFields() ));
+        }
+
         /// <summary>
         /// Loads all the related references onto the instance. E.g:
         /// <para>db.LoadReferences(customer)</para> 

src/ServiceStack.OrmLite/OrmLiteUtils.cs

@@ -13,6 +13,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Data;
+using System.Linq;
 using System.Text;
 using ServiceStack.Logging;
 using ServiceStack.Text;
@@ -659,5 +660,10 @@ public static List<string> ParseTokens(this string expr)
 
             return to;
         }
+
+        public static string[] AllAnonFields(this Type type)
+        {
+            return type.GetPublicProperties().Select(x => x.Name).ToArray();
+        }
     }
 }

tests/ServiceStack.OrmLite.Tests/LoadReferencesTests.cs

@@ -659,7 +659,11 @@ public void Can_load_only_included_references()
             // Test LoadSingleById
             var dbCustomer = db.LoadSingleById<Customer>(customer.Id, include: new[] { "PrimaryAddress" });
             Assert.That(dbCustomer.Name, Is.EqualTo("Customer 1"));
+            Assert.That(dbCustomer.Orders, Is.Null);
+            Assert.That(dbCustomer.PrimaryAddress, Is.Not.Null);
 
+            dbCustomer = db.LoadSingleById<Customer>(customer.Id, include: x => new { x.PrimaryAddress });
+            Assert.That(dbCustomer.Name, Is.EqualTo("Customer 1"));
             Assert.That(dbCustomer.Orders, Is.Null);
             Assert.That(dbCustomer.PrimaryAddress, Is.Not.Null);