From 167ad203cbfb0a3bed19069b418ccb35814d506d Mon Sep 17 00:00:00 2001
From: slene <vslene@gmail.com>
Date: Fri, 8 Nov 2013 22:19:01 +0800
Subject: [PATCH] orm #276

---
 orm/db.go       | 34 ++++++++++++++++++++++++++++++----
 orm/orm_test.go |  9 +++++++--
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/orm/db.go b/orm/db.go
index a5f6471a..7d4833e2 100644
--- a/orm/db.go
+++ b/orm/db.go
@@ -705,7 +705,13 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 				ind.Set(mind)
 			} else {
 				if cnt == 0 {
-					slice = reflect.New(ind.Type()).Elem()
+					// you can use a empty & caped container list
+					// orm will not replace it
+					if ind.Len() != 0 {
+						// if container is not empty
+						// create a new one
+						slice = reflect.New(ind.Type()).Elem()
+					}
 				}
 
 				if isPtr {
@@ -718,8 +724,16 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 		cnt++
 	}
 
-	if one == false && cnt > 0 {
-		ind.Set(slice)
+	if one == false {
+		if cnt > 0 {
+			ind.Set(slice)
+		} else {
+			// when a result is empty and container is nil
+			// to set a empty container
+			if ind.IsNil() {
+				ind.Set(reflect.MakeSlice(ind.Type(), 0, 0))
+			}
+		}
 	}
 
 	return cnt, nil
@@ -1058,12 +1072,24 @@ func (d *dbBase) ReadValues(q dbQuerier, qs *querySet, mi *modelInfo, cond *Cond
 	)
 
 	typ := 0
-	switch container.(type) {
+	switch v := container.(type) {
 	case *[]Params:
+		d := *v
+		if len(d) == 0 {
+			maps = d
+		}
 		typ = 1
 	case *[]ParamsList:
+		d := *v
+		if len(d) == 0 {
+			lists = d
+		}
 		typ = 2
 	case *ParamsList:
+		d := *v
+		if len(d) == 0 {
+			list = d
+		}
 		typ = 3
 	default:
 		panic(fmt.Errorf("unsupport read values type `%T`", container))
diff --git a/orm/orm_test.go b/orm/orm_test.go
index 25093cf2..5448e032 100644
--- a/orm/orm_test.go
+++ b/orm/orm_test.go
@@ -696,8 +696,13 @@ func TestAll(t *testing.T) {
 
 	qs = dORM.QueryTable("user")
 	num, err = qs.Filter("user_name", "nothing").All(&users)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 0))
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 0))
+
+	var users3 []*User
+	qs = dORM.QueryTable("user")
+	num, err = qs.Filter("user_name", "nothing").All(&users3)
+	throwFailNow(t, AssertIs(users3 == nil, false))
 }
 
 func TestOne(t *testing.T) {