Relax generic constrain on UpdateOnly

Author: mythz

src/ServiceStack.OrmLite/Expressions/WriteExpressionCommandExtensions.cs

@@ -32,8 +32,8 @@ internal static void UpdateOnlySql<T>(this IDbCommand dbCmd, T model, SqlExpress
                 dbCmd.CommandText += " " + onlyFields.WhereExpression;
         }
 
-        internal static int UpdateOnly<T, TKey>(this IDbCommand dbCmd, T obj,
-            Expression<Func<T, TKey>> onlyFields = null,
+        internal static int UpdateOnly<T>(this IDbCommand dbCmd, T obj,
+            Expression<Func<T, object>> onlyFields = null,
             Expression<Func<T, bool>> where = null)
         {
             if (onlyFields == null)

src/ServiceStack.OrmLite/OrmLiteWriteExpressionsApi.cs

@@ -61,8 +61,8 @@ public static int UpdateOnly<T>(this IDbConnection dbConn,
         ///   db.UpdateOnly(new Person { FirstName = "JJ" }, p => p.FirstName);
         ///   UPDATE "Person" SET "FirstName" = 'JJ'
         /// </summary>
-        public static int UpdateOnly<T, TKey>(this IDbConnection dbConn, T obj,
-            Expression<Func<T, TKey>> onlyFields = null,
+        public static int UpdateOnly<T>(this IDbConnection dbConn, T obj,
+            Expression<Func<T, object>> onlyFields = null,
             Expression<Func<T, bool>> where = null)
         {
             return dbConn.Exec(dbCmd => dbCmd.UpdateOnly(obj, onlyFields, where));