From f9a86e9148fab7af0f932d8c1350683087d794a4 Mon Sep 17 00:00:00 2001
From: a631807682 <631807682@qq.com>
Date: Thu, 14 Apr 2022 19:14:46 +0800
Subject: [PATCH] fix: FindInBatches Limit zero

---
 finisher_api.go     |  2 +-
 tests/query_test.go | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/finisher_api.go b/finisher_api.go
index bc44dbd4..fb765d33 100644
--- a/finisher_api.go
+++ b/finisher_api.go
@@ -187,7 +187,7 @@ func (db *DB) FindInBatches(dest interface{}, batchSize int, fc func(tx *DB, bat
 		if limit, ok := c.Expression.(clause.Limit); ok {
 			totalSize = limit.Limit
 
-			if batchSize > totalSize {
+			if totalSize > 0 && batchSize > totalSize {
 				batchSize = totalSize
 			}
 
diff --git a/tests/query_test.go b/tests/query_test.go
index 9dd61bab..f66cf83a 100644
--- a/tests/query_test.go
+++ b/tests/query_test.go
@@ -330,14 +330,24 @@ func TestFindInBatchesWithOffsetLimit(t *testing.T) {
 		AssertEqual(t, results[i], targetUsers[i])
 	}
 
+	var sub1 []User
 	// limit < batchSize
-	if result := DB.Limit(5).Where("name = ?", users[0].Name).FindInBatches(&sub, 10, func(tx *gorm.DB, batch int) error {
+	if result := DB.Limit(5).Where("name = ?", users[0].Name).FindInBatches(&sub1, 10, func(tx *gorm.DB, batch int) error {
 		return nil
 	}); result.Error != nil || result.RowsAffected != 5 {
 		t.Errorf("Failed to batch find, got error %v, rows affected: %v", result.Error, result.RowsAffected)
 	}
 
-	if result := DB.Limit(4).Where("name = ?", users[0].Name).FindInBatches(&sub, 2, func(tx *gorm.DB, batch int) error {
+	var sub2 []User
+	// only offset
+	if result := DB.Offset(3).Where("name = ?", users[0].Name).FindInBatches(&sub2, 2, func(tx *gorm.DB, batch int) error {
+		return nil
+	}); result.Error != nil || result.RowsAffected != 7 {
+		t.Errorf("Failed to batch find, got error %v, rows affected: %v", result.Error, result.RowsAffected)
+	}
+
+	var sub3 []User
+	if result := DB.Limit(4).Where("name = ?", users[0].Name).FindInBatches(&sub3, 2, func(tx *gorm.DB, batch int) error {
 		return nil
 	}); result.Error != nil || result.RowsAffected != 4 {
 		t.Errorf("Failed to batch find, got error %v, rows affected: %v", result.Error, result.RowsAffected)