diff --git a/README.md b/README.md
index 9a671386..b0dcb7bd 100644
--- a/README.md
+++ b/README.md
@@ -570,7 +570,7 @@ db.Model(&user).Related(&card, "CreditCard")
 //// SELECT * FROM credit_cards WHERE user_id = 123; // 123 is user's primary key
 // CreditCard is user's field name, it means get user's CreditCard relations and fill it into variable card
 // If the field name is same as the variable's type name, like above example, it could be omitted, like:
-db.Model(&user).Related(&creditCard, "CreditCard")
+db.Model(&user).Related(&card)
 ```
 
 ### Belongs To
@@ -859,7 +859,7 @@ db.Where("name = ?", "jinzhu").Or("name = ?", "jinzhu 2").Find(&users).Count(&co
 //// SELECT * from USERS WHERE name = 'jinzhu' OR name = 'jinzhu 2'; (users)
 //// SELECT count(*) FROM users WHERE name = 'jinzhu' OR name = 'jinzhu 2'; (count)
 
-db.Model(User{}).Where("name = ?", "jinzhu").Count(&count)
+db.Model(&User{}).Where("name = ?", "jinzhu").Count(&count)
 //// SELECT count(*) FROM users WHERE name = 'jinzhu'; (count)
 
 db.Table("deleted_users").Count(&count)
diff --git a/preload_test.go b/preload_test.go
index 2fc441a9..7bc3f389 100644
--- a/preload_test.go
+++ b/preload_test.go
@@ -1064,6 +1064,64 @@ func TestNestedManyToManyPreload3(t *testing.T) {
 	}
 }
 
+func TestNestedManyToManyPreload4(t *testing.T) {
+	type (
+		Level4 struct {
+			ID       uint
+			Value    string
+			Level3ID uint
+		}
+		Level3 struct {
+			ID      uint
+			Value   string
+			Level4s []*Level4
+		}
+		Level2 struct {
+			ID      uint
+			Value   string
+			Level3s []*Level3 `gorm:"many2many:level2_level3;"`
+		}
+		Level1 struct {
+			ID      uint
+			Value   string
+			Level2s []*Level2 `gorm:"many2many:level1_level2;"`
+		}
+	)
+
+	DB.DropTableIfExists(&Level1{})
+	DB.DropTableIfExists(&Level2{})
+	DB.DropTableIfExists(&Level3{})
+	DB.DropTableIfExists(&Level4{})
+	DB.DropTableIfExists("level1_level2")
+	DB.DropTableIfExists("level2_level3")
+
+	dummy := Level1{
+		Value: "Level1",
+		Level2s: []*Level2{&Level2{
+			Value: "Level2",
+			Level3s: []*Level3{&Level3{
+				Value: "Level3",
+				Level4s: []*Level4{&Level4{
+					Value: "Level4",
+				}},
+			}},
+		}},
+	}
+
+	if err := DB.AutoMigrate(&Level4{}, &Level3{}, &Level2{}, &Level1{}).Error; err != nil {
+		t.Error(err)
+	}
+
+	if err := DB.Save(&dummy).Error; err != nil {
+		t.Error(err)
+	}
+
+	var level1 Level1
+	if err := DB.Preload("Level2s").Preload("Level2s.Level3s").Preload("Level2s.Level3s.Level4s").First(&level1).Error; err != nil {
+		t.Error(err)
+	}
+}
+
 func TestManyToManyPreloadForPointer(t *testing.T) {
 	type (
 		Level1 struct {
diff --git a/query_test.go b/query_test.go
index b762dee5..b376dc82 100644
--- a/query_test.go
+++ b/query_test.go
@@ -155,6 +155,14 @@ func TestSearchWithPlainSQL(t *testing.T) {
 		t.Errorf("Should found 1 users, but got %v", len(users))
 	}
 
+	if err := DB.Where("id IN (?)", []string{}).Find(&users).Error; err != nil {
+		t.Error("no error should happen when query with empty slice, but got: ", err)
+	}
+
+	if err := DB.Not("id IN (?)", []string{}).Find(&users).Error; err != nil {
+		t.Error("no error should happen when query with empty slice, but got: ", err)
+	}
+
 	if DB.Where("name = ?", "none existing").Find(&[]User{}).RecordNotFound() {
 		t.Errorf("Should not get RecordNotFound error when looking for none existing records")
 	}
diff --git a/scope_private.go b/scope_private.go
index 138bd6fd..4fd48833 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -27,7 +27,7 @@ func (scope *Scope) buildWhereCondition(clause map[string]interface{}) (str stri
 	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, sql.NullInt64:
 		return scope.primaryCondition(scope.AddToVars(value))
 	case []int, []int8, []int16, []int32, []int64, []uint, []uint8, []uint16, []uint32, []uint64, []string, []interface{}:
-		str = fmt.Sprintf("(%v in (?))", scope.Quote(scope.PrimaryKey()))
+		str = fmt.Sprintf("(%v IN (?))", scope.Quote(scope.PrimaryKey()))
 		clause["args"] = []interface{}{value}
 	case map[string]interface{}:
 		var sqls []string
@@ -55,13 +55,14 @@ func (scope *Scope) buildWhereCondition(clause map[string]interface{}) (str stri
 		case reflect.Slice: // For where("id in (?)", []int64{1,2})
 			if bytes, ok := arg.([]byte); ok {
 				str = strings.Replace(str, "?", scope.AddToVars(bytes), 1)
-			} else {
-				values := reflect.ValueOf(arg)
+			} else if values := reflect.ValueOf(arg); values.Len() > 0 {
 				var tempMarks []string
 				for i := 0; i < values.Len(); i++ {
 					tempMarks = append(tempMarks, scope.AddToVars(values.Index(i).Interface()))
 				}
 				str = strings.Replace(str, "?", strings.Join(tempMarks, ","), 1)
+			} else {
+				str = strings.Replace(str, "?", scope.AddToVars(Expr("NULL")), 1)
 			}
 		default:
 			if valuer, ok := interface{}(arg).(driver.Valuer); ok {
@@ -84,7 +85,7 @@ func (scope *Scope) buildNotCondition(clause map[string]interface{}) (str string
 		if regexp.MustCompile("^\\s*\\d+\\s*$").MatchString(value) {
 			id, _ := strconv.Atoi(value)
 			return fmt.Sprintf("(%v <> %v)", scope.Quote(primaryKey), id)
-		} else if regexp.MustCompile("(?i) (=|<>|>|<|LIKE|IS) ").MatchString(value) {
+		} else if regexp.MustCompile("(?i) (=|<>|>|<|LIKE|IS|IN) ").MatchString(value) {
 			str = fmt.Sprintf(" NOT (%v) ", value)
 			notEqualSql = fmt.Sprintf("NOT (%v)", value)
 		} else {
@@ -123,12 +124,17 @@ func (scope *Scope) buildNotCondition(clause map[string]interface{}) (str string
 	for _, arg := range args {
 		switch reflect.ValueOf(arg).Kind() {
 		case reflect.Slice: // For where("id in (?)", []int64{1,2})
-			values := reflect.ValueOf(arg)
-			var tempMarks []string
-			for i := 0; i < values.Len(); i++ {
-				tempMarks = append(tempMarks, scope.AddToVars(values.Index(i).Interface()))
+			if bytes, ok := arg.([]byte); ok {
+				str = strings.Replace(str, "?", scope.AddToVars(bytes), 1)
+			} else if values := reflect.ValueOf(arg); values.Len() > 0 {
+				var tempMarks []string
+				for i := 0; i < values.Len(); i++ {
+					tempMarks = append(tempMarks, scope.AddToVars(values.Index(i).Interface()))
+				}
+				str = strings.Replace(str, "?", strings.Join(tempMarks, ","), 1)
+			} else {
+				str = strings.Replace(str, "?", scope.AddToVars(Expr("NULL")), 1)
 			}
-			str = strings.Replace(str, "?", strings.Join(tempMarks, ","), 1)
 		default:
 			if scanner, ok := interface{}(arg).(driver.Valuer); ok {
 				arg, _ = scanner.Value()