From 7948705181040f108f8cc34af50047e8a39b70a0 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Sun, 27 Oct 2013 11:44:47 +0800
Subject: [PATCH] Yay, Offset works

---
 README.md   |  1 -
 orm.go      | 10 +++++++---
 orm_test.go |  9 +++++++++
 sql.go      | 10 +++++++++-
 4 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 16e6f275..a98f3421 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,6 @@
 Yet Another ORM library for Go, aims for developer friendly
 
 ## TODO
-* Limit
 * Offset
 * Or query
 * Not query
diff --git a/orm.go b/orm.go
index ab526696..2ad238bc 100644
--- a/orm.go
+++ b/orm.go
@@ -21,7 +21,7 @@ type Orm struct {
 	whereClause []map[string]interface{}
 	selectStr   string
 	orderStrs   []string
-	offsetInt   int
+	offsetStr   string
 	limitStr    string
 	operation   string
 }
@@ -57,9 +57,13 @@ func (s *Orm) Limit(value interface{}) *Orm {
 func (s *Orm) Offset(value interface{}) *Orm {
 	switch value := value.(type) {
 	case string:
-		s.offsetInt, _ = strconv.Atoi(value)
+		s.offsetStr = value
 	case int:
-		s.offsetInt = value
+		if value < 0 {
+			s.offsetStr = ""
+		} else {
+			s.offsetStr = strconv.Itoa(value)
+		}
 	default:
 		s.Error = errors.New("Can' understand the value of Offset, Should be int")
 	}
diff --git a/orm_test.go b/orm_test.go
index 5774507c..21d79620 100644
--- a/orm_test.go
+++ b/orm_test.go
@@ -264,3 +264,12 @@ func TestLimit(t *testing.T) {
 		t.Errorf("Limit should works perfectly")
 	}
 }
+
+func TestOffset(t *testing.T) {
+	var users1, users2, users3, users4 []User
+	db.Order("age desc").Find(&users1).Offset(3).Find(&users2).Offset(5).Find(&users3).Offset(-1).Find(&users4)
+
+	if !((len(users1) == len(users4)) && (len(users1)-len(users2) == 3) && (len(users1)-len(users3) == 5)) {
+		t.Errorf("Offset should works perfectly")
+	}
+}
diff --git a/sql.go b/sql.go
index 36321155..9ee87c6b 100644
--- a/sql.go
+++ b/sql.go
@@ -231,8 +231,16 @@ func (s *Orm) limitSql() string {
 	}
 }
 
+func (s *Orm) offsetSql() string {
+	if len(s.offsetStr) == 0 {
+		return ""
+	} else {
+		return " OFFSET " + s.offsetStr
+	}
+}
+
 func (s *Orm) combinedSql() string {
-	return s.whereSql() + s.orderSql() + s.limitSql()
+	return s.whereSql() + s.orderSql() + s.limitSql() + s.offsetSql()
 }
 
 func (s *Orm) addToVars(value interface{}) string {