fix AutoIncrement issues with SQL Server 2012

Author: mythz

src/ServiceStack.OrmLite.SqlServer/SqlServer2012OrmLiteDialectProvider.cs

@@ -25,15 +25,17 @@ public override bool DoesSequenceExist(IDbCommand dbCmd, string sequenceName)
 
         protected override string GetAutoIncrementDefinition(FieldDefinition fieldDef)
         {
-            if (fieldDef.AutoIncrement && !string.IsNullOrEmpty(fieldDef.Sequence))
+            if (!string.IsNullOrEmpty(fieldDef.Sequence))
                 return $"DEFAULT NEXT VALUE FOR {Sequence(NamingStrategy.GetSchemaName(GetModel(fieldDef.PropertyInfo?.ReflectedType)), fieldDef.Sequence)}";
             else
                 return AutoIncrementDefinition;
         }
 
-        protected override bool ShouldSkipInsert(FieldDefinition fieldDef) => fieldDef.ShouldSkipInsert() && !fieldDef.AutoIncrement && string.IsNullOrEmpty(fieldDef.Sequence);
+        protected override bool ShouldSkipInsert(FieldDefinition fieldDef) => 
+            fieldDef.ShouldSkipInsert() && string.IsNullOrEmpty(fieldDef.Sequence);
 
-        protected override bool SupportsSequences(FieldDefinition fieldDef) => fieldDef.AutoIncrement || !string.IsNullOrEmpty(fieldDef.Sequence);
+        protected override bool SupportsSequences(FieldDefinition fieldDef) => 
+            !string.IsNullOrEmpty(fieldDef.Sequence);
 
         public override List<string> ToCreateSequenceStatements(Type tableType)
         {

src/ServiceStack.OrmLite.SqlServer/SqlServerOrmLiteDialectProvider.cs

@@ -313,7 +313,8 @@ protected string Sequence(string schema, string sequence)
         protected virtual bool ShouldReturnOnInsert(ModelDefinition modelDef, FieldDefinition fieldDef) =>
             fieldDef.ReturnOnInsert || (fieldDef.IsPrimaryKey && fieldDef.AutoIncrement && modelDef.HasReturnAttribute);
 
-        protected virtual bool ShouldSkipInsert(FieldDefinition fieldDef) => fieldDef.ShouldSkipInsert();
+        protected virtual bool ShouldSkipInsert(FieldDefinition fieldDef) => 
+            fieldDef.ShouldSkipInsert();
 
         protected virtual bool SupportsSequences(FieldDefinition fieldDef) => false;
 

src/ServiceStack.OrmLite/OrmLiteWriteCommandExtensions.cs

@@ -645,33 +645,31 @@ internal static long Insert<T>(this IDbCommand dbCmd, T obj, Action<IDbCommand>
             if (modelDef.HasReturnAttribute)
             {
                 using (var reader = dbCmd.ExecReader(dbCmd.CommandText))
+                using (reader)
                 {
-                    using (reader)
+                    if (reader.Read())
                     {
-                        if (reader.Read())
+                        var values = new object[reader.FieldCount];
+                        var indexCache = reader.GetIndexFieldsCache(ModelDefinition<T>.Definition, dialectProvider);
+                        obj.PopulateWithSqlReader(dialectProvider, reader, indexCache, values);
+                        if ((modelDef.PrimaryKey != null) && modelDef.PrimaryKey.AutoIncrement)
                         {
-                            var values = new object[reader.FieldCount];
-                            var indexCache = reader.GetIndexFieldsCache(ModelDefinition<T>.Definition, dialectProvider);
-                            obj.PopulateWithSqlReader(dialectProvider, reader, indexCache, values);
-                            if ((modelDef.PrimaryKey != null) && modelDef.PrimaryKey.AutoIncrement)
-                            {
-                                var id = modelDef.GetPrimaryKey(obj);
-                                return Convert.ToInt64(id);
-                            }
+                            var id = modelDef.GetPrimaryKey(obj);
+                            return Convert.ToInt64(id);
                         }
-                        return 0;
                     }
+                    return 0;
                 }
             }
-            else
+
             if (selectIdentity)
             {
                 dbCmd.CommandText += dialectProvider.GetLastInsertIdSqlSuffix<T>();
 
                 return dbCmd.ExecLongScalar();
             }
-            else
-                return dbCmd.ExecNonQuery();
+
+            return dbCmd.ExecNonQuery();
         }
 
         internal static void Insert<T>(this IDbCommand dbCmd, Action<IDbCommand> commandFilter, params T[] objs)