From 5b671a84b63b51114df6712353391bba13c8ea3e Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Sat, 2 Nov 2013 18:25:01 +0800
Subject: [PATCH] Error message when set primary key

---
 do.go        |  4 +++-
 gorm_test.go | 12 +++++++-----
 model.go     |  5 ++++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/do.go b/do.go
index a6fe828e..787ce376 100644
--- a/do.go
+++ b/do.go
@@ -159,7 +159,9 @@ func (s *Do) create() {
 
 		if !s.hasError() {
 			result := reflect.Indirect(reflect.ValueOf(s.value))
-			setFieldValue(result.FieldByName(s.model.primaryKey()), id)
+			if !setFieldValue(result.FieldByName(s.model.primaryKey()), id) {
+				fmt.Printf("Can't set primary key for %#v\n", result.Interface())
+			}
 			s.saveAfterAssociations()
 
 			s.err(s.model.callMethod("AfterCreate"))
diff --git a/gorm_test.go b/gorm_test.go
index 6cacb7de..ece9db44 100644
--- a/gorm_test.go
+++ b/gorm_test.go
@@ -1002,15 +1002,17 @@ type Category struct {
 }
 
 type Post struct {
-	Id       int64
-	Title    string
-	Body     string
-	Comments []Comment
-	Category Category
+	Id         int64
+	CategoryId int64
+	Title      string
+	Body       string
+	Comments   []Comment
+	Category   Category
 }
 
 type Comment struct {
 	Id      int64
+	PostId  int64
 	Content string
 	Post    Post
 }
diff --git a/model.go b/model.go
index 8c742b14..f4b85e19 100644
--- a/model.go
+++ b/model.go
@@ -309,7 +309,7 @@ func (m *Model) afterAssociations() (fields []Field) {
 	return
 }
 
-func setFieldValue(field reflect.Value, value interface{}) {
+func setFieldValue(field reflect.Value, value interface{}) bool {
 	if field.IsValid() && field.CanAddr() {
 		switch field.Kind() {
 		case reflect.Int, reflect.Int32, reflect.Int64:
@@ -320,5 +320,8 @@ func setFieldValue(field reflect.Value, value interface{}) {
 		default:
 			field.Set(reflect.ValueOf(value))
 		}
+		return true
+	} else {
+		return false
 	}
 }