From 468152d45b66ab30091624f32f5b989204e04c40 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Wed, 16 Dec 2020 19:33:35 +0800
Subject: [PATCH] Add DisableNestedTransaction support

---
 finisher_api.go           | 16 +++++-----
 gorm.go                   | 31 +++++++++++--------
 tests/transaction_test.go | 63 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+), 19 deletions(-)

diff --git a/finisher_api.go b/finisher_api.go
index 98a877f2..03bcd20f 100644
--- a/finisher_api.go
+++ b/finisher_api.go
@@ -498,13 +498,15 @@ func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err er
 
 	if committer, ok := db.Statement.ConnPool.(TxCommitter); ok && committer != nil {
 		// nested transaction
-		err = db.SavePoint(fmt.Sprintf("sp%p", fc)).Error
-		defer func() {
-			// Make sure to rollback when panic, Block error or Commit error
-			if panicked || err != nil {
-				db.RollbackTo(fmt.Sprintf("sp%p", fc))
-			}
-		}()
+		if !db.DisableNestedTransaction {
+			err = db.SavePoint(fmt.Sprintf("sp%p", fc)).Error
+			defer func() {
+				// Make sure to rollback when panic, Block error or Commit error
+				if panicked || err != nil {
+					db.RollbackTo(fmt.Sprintf("sp%p", fc))
+				}
+			}()
+		}
 
 		if err == nil {
 			err = fc(db.Session(&Session{}))
diff --git a/gorm.go b/gorm.go
index ae1cf2c9..ae94daf4 100644
--- a/gorm.go
+++ b/gorm.go
@@ -34,6 +34,8 @@ type Config struct {
 	DisableAutomaticPing bool
 	// DisableForeignKeyConstraintWhenMigrating
 	DisableForeignKeyConstraintWhenMigrating bool
+	// DisableNestedTransaction disable nested transaction
+	DisableNestedTransaction bool
 	// AllowGlobalUpdate allow global update
 	AllowGlobalUpdate bool
 	// QueryFields executes the SQL query with all fields of the table
@@ -65,18 +67,19 @@ type DB struct {
 
 // Session session config when create session with Session() method
 type Session struct {
-	DryRun                 bool
-	PrepareStmt            bool
-	NewDB                  bool
-	SkipHooks              bool
-	SkipDefaultTransaction bool
-	AllowGlobalUpdate      bool
-	FullSaveAssociations   bool
-	QueryFields            bool
-	Context                context.Context
-	Logger                 logger.Interface
-	NowFunc                func() time.Time
-	CreateBatchSize        int
+	DryRun                   bool
+	PrepareStmt              bool
+	NewDB                    bool
+	SkipHooks                bool
+	SkipDefaultTransaction   bool
+	DisableNestedTransaction bool
+	AllowGlobalUpdate        bool
+	FullSaveAssociations     bool
+	QueryFields              bool
+	Context                  context.Context
+	Logger                   logger.Interface
+	NowFunc                  func() time.Time
+	CreateBatchSize          int
 }
 
 // Open initialize db session based on dialector
@@ -206,6 +209,10 @@ func (db *DB) Session(config *Session) *DB {
 		tx.Statement.SkipHooks = true
 	}
 
+	if config.DisableNestedTransaction {
+		txConfig.DisableNestedTransaction = true
+	}
+
 	if !config.NewDB {
 		tx.clone = 2
 	}
diff --git a/tests/transaction_test.go b/tests/transaction_test.go
index 334600b8..c17fea3b 100644
--- a/tests/transaction_test.go
+++ b/tests/transaction_test.go
@@ -283,6 +283,69 @@ func TestNestedTransactionWithBlock(t *testing.T) {
 	}
 }
 
+func TestDisabledNestedTransaction(t *testing.T) {
+	var (
+		user  = *GetUser("transaction-nested", Config{})
+		user1 = *GetUser("transaction-nested-1", Config{})
+		user2 = *GetUser("transaction-nested-2", Config{})
+	)
+
+	if err := DB.Session(&gorm.Session{DisableNestedTransaction: true}).Transaction(func(tx *gorm.DB) error {
+		tx.Create(&user)
+
+		if err := tx.First(&User{}, "name = ?", user.Name).Error; err != nil {
+			t.Fatalf("Should find saved record")
+		}
+
+		if err := tx.Transaction(func(tx1 *gorm.DB) error {
+			tx1.Create(&user1)
+
+			if err := tx1.First(&User{}, "name = ?", user1.Name).Error; err != nil {
+				t.Fatalf("Should find saved record")
+			}
+
+			return errors.New("rollback")
+		}); err == nil {
+			t.Fatalf("nested transaction should returns error")
+		}
+
+		if err := tx.First(&User{}, "name = ?", user1.Name).Error; err != nil {
+			t.Fatalf("Should not rollback record if disabled nested transaction support")
+		}
+
+		if err := tx.Transaction(func(tx2 *gorm.DB) error {
+			tx2.Create(&user2)
+
+			if err := tx2.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+				t.Fatalf("Should find saved record")
+			}
+
+			return nil
+		}); err != nil {
+			t.Fatalf("nested transaction returns error: %v", err)
+		}
+
+		if err := tx.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+			t.Fatalf("Should find saved record")
+		}
+		return nil
+	}); err != nil {
+		t.Fatalf("no error should return, but got %v", err)
+	}
+
+	if err := DB.First(&User{}, "name = ?", user.Name).Error; err != nil {
+		t.Fatalf("Should find saved record")
+	}
+
+	if err := DB.First(&User{}, "name = ?", user1.Name).Error; err != nil {
+		t.Fatalf("Should not rollback record if disabled nested transaction support")
+	}
+
+	if err := DB.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+		t.Fatalf("Should find saved record")
+	}
+}
+
 func TestTransactionOnClosedConn(t *testing.T) {
 	DB, err := OpenTestConnection()
 	if err != nil {