From a8db54afd665dafe763e0d2d881d57fb602fd30d Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Mon, 16 Nov 2020 21:42:30 +0800
Subject: [PATCH] Add CreateInBatches supports

---
 finisher_api.go      | 23 +++++++++++++++++++++++
 tests/create_test.go | 26 ++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/finisher_api.go b/finisher_api.go
index 67423b23..c9e2a3b2 100644
--- a/finisher_api.go
+++ b/finisher_api.go
@@ -21,6 +21,29 @@ func (db *DB) Create(value interface{}) (tx *DB) {
 	return
 }
 
+// CreateInBatches insert the value in batches into database
+func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
+	reflectValue := reflect.Indirect(reflect.ValueOf(value))
+
+	switch reflectValue.Kind() {
+	case reflect.Slice, reflect.Array:
+		tx = db.getInstance()
+		for i := 0; i < reflectValue.Len(); i += batchSize {
+			tx.AddError(tx.Transaction(func(tx *DB) error {
+				ends := i + batchSize
+				if ends > reflectValue.Len() {
+					ends = reflectValue.Len()
+				}
+
+				return tx.Create(reflectValue.Slice(i, ends).Interface()).Error
+			}))
+		}
+	default:
+		return db.Create(value)
+	}
+	return
+}
+
 // Save update value in database, if the value doesn't have primary key, will insert it
 func (db *DB) Save(value interface{}) (tx *DB) {
 	tx = db.getInstance()
diff --git a/tests/create_test.go b/tests/create_test.go
index 00674eec..8d005d0b 100644
--- a/tests/create_test.go
+++ b/tests/create_test.go
@@ -40,6 +40,32 @@ func TestCreate(t *testing.T) {
 	}
 }
 
+func TestCreateInBatches(t *testing.T) {
+	users := []User{
+		*GetUser("create_in_batches_1", Config{Account: true, Pets: 2, Toys: 3, Company: true, Manager: true, Team: 0, Languages: 1, Friends: 1}),
+		*GetUser("create_in_batches_2", Config{Account: false, Pets: 2, Toys: 4, Company: false, Manager: false, Team: 1, Languages: 3, Friends: 5}),
+		*GetUser("create_in_batches_3", Config{Account: true, Pets: 0, Toys: 3, Company: true, Manager: false, Team: 4, Languages: 0, Friends: 1}),
+		*GetUser("create_in_batches_4", Config{Account: true, Pets: 3, Toys: 0, Company: false, Manager: true, Team: 0, Languages: 3, Friends: 0}),
+		*GetUser("create_in_batches_5", Config{Account: false, Pets: 0, Toys: 3, Company: true, Manager: false, Team: 1, Languages: 3, Friends: 1}),
+		*GetUser("create_in_batches_6", Config{Account: true, Pets: 4, Toys: 3, Company: false, Manager: true, Team: 1, Languages: 3, Friends: 0}),
+	}
+
+	DB.CreateInBatches(&users, 2)
+
+	for _, user := range users {
+		if user.ID == 0 {
+			t.Fatalf("failed to fill user's ID, got %v", user.ID)
+		} else {
+			var newUser User
+			if err := DB.Where("id = ?", user.ID).Preload(clause.Associations).First(&newUser).Error; err != nil {
+				t.Fatalf("errors happened when query: %v", err)
+			} else {
+				CheckUser(t, newUser, user)
+			}
+		}
+	}
+}
+
 func TestCreateFromMap(t *testing.T) {
 	if err := DB.Model(&User{}).Create(map[string]interface{}{"Name": "create_from_map", "Age": 18}).Error; err != nil {
 		t.Fatalf("failed to create data from map, got error: %v", err)