From 48b395b760d86fddad7480972791444494a8ae68 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Thu, 3 Sep 2020 11:32:30 +0800
Subject: [PATCH] returns ErrEmptySlice when creating with zero length slice

---
 callbacks/create.go  |  5 +++++
 callbacks/helper.go  |  5 +++++
 errors.go            |  2 ++
 tests/create_test.go | 12 ++++++++++++
 tests/go.mod         |  2 ++
 5 files changed, 26 insertions(+)

diff --git a/callbacks/create.go b/callbacks/create.go
index 5de19d35..e37c2c60 100644
--- a/callbacks/create.go
+++ b/callbacks/create.go
@@ -252,6 +252,11 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 			stmt.SQL.Grow(stmt.ReflectValue.Len() * 15)
 			values.Values = make([][]interface{}, stmt.ReflectValue.Len())
 			defaultValueFieldsHavingValue := map[*schema.Field][]interface{}{}
+			if stmt.ReflectValue.Len() == 0 {
+				stmt.AddError(gorm.ErrEmptySlice)
+				return
+			}
+
 			for i := 0; i < stmt.ReflectValue.Len(); i++ {
 				rv := reflect.Indirect(stmt.ReflectValue.Index(i))
 				values.Values[i] = make([]interface{}, len(values.Columns))
diff --git a/callbacks/helper.go b/callbacks/helper.go
index e0a66dd2..09ec4582 100644
--- a/callbacks/helper.go
+++ b/callbacks/helper.go
@@ -46,6 +46,11 @@ func ConvertSliceOfMapToValuesForCreate(stmt *gorm.Statement, mapValues []map[st
 		selectColumns, restricted = stmt.SelectAndOmitColumns(true, false)
 	)
 
+	if len(mapValues) == 0 {
+		stmt.AddError(gorm.ErrEmptySlice)
+		return
+	}
+
 	for idx, mapValue := range mapValues {
 		for k, v := range mapValue {
 			if stmt.Schema != nil {
diff --git a/errors.go b/errors.go
index 32ff8ec1..508f6957 100644
--- a/errors.go
+++ b/errors.go
@@ -27,4 +27,6 @@ var (
 	ErrRegistered = errors.New("registered")
 	// ErrInvalidField invalid field
 	ErrInvalidField = errors.New("invalid field")
+	// ErrEmptySlice empty slice found
+	ErrEmptySlice = errors.New("empty slice found")
 )
diff --git a/tests/create_test.go b/tests/create_test.go
index ab0a78d4..59fdd8f1 100644
--- a/tests/create_test.go
+++ b/tests/create_test.go
@@ -287,6 +287,18 @@ func TestCreateEmptyStruct(t *testing.T) {
 	}
 }
 
+func TestCreateEmptySlice(t *testing.T) {
+	var data = []User{}
+	if err := DB.Create(&data).Error; err != gorm.ErrEmptySlice {
+		t.Errorf("no data should be created, got %v", err)
+	}
+
+	var sliceMap = []map[string]interface{}{}
+	if err := DB.Model(&User{}).Create(&sliceMap).Error; err != gorm.ErrEmptySlice {
+		t.Errorf("no data should be created, got %v", err)
+	}
+}
+
 func TestCreateWithExistingTimestamp(t *testing.T) {
 	user := User{Name: "CreateUserExistingTimestamp"}
 	curTime := now.MustParse("2016-01-01")
diff --git a/tests/go.mod b/tests/go.mod
index 30a7dda7..2b336850 100644
--- a/tests/go.mod
+++ b/tests/go.mod
@@ -16,3 +16,5 @@ require (
 replace gorm.io/gorm => ../
 
 replace github.com/jackc/pgx/v4 => github.com/jinzhu/pgx/v4 v4.8.2
+
+replace gorm.io/driver/sqlserver => /Users/jinzhu/Projects/jinzhu/sqlserver