fix(database/gdb): fix transaction propagation feature (#4199)

contrib/drivers/mysql/mysql_z_unit_transaction_test.go

@@ -1286,8 +1286,7 @@ func Test_Transaction_Propagation(t *testing.T) {
 				Propagation: gdb.PropagationNotSupported,
 			}, func(ctx context.Context, tx2 gdb.TX) error {
 				// Should execute without transaction
-				t.Assert(tx2, nil)
+				_, err = db.Insert(ctx, table, g.Map{
-				_, err := db.Insert(ctx, table, g.Map{
 					"id":       9,
 					"passport": "non_tx_record",
 				})
@@ -1346,8 +1345,6 @@ func Test_Transaction_Propagation(t *testing.T) {
 		err := db.TransactionWithOptions(ctx, gdb.TxOptions{
 			Propagation: gdb.PropagationNever,
 		}, func(ctx context.Context, tx gdb.TX) error {
-			// Should execute without transaction
-			t.Assert(tx, nil)
 			_, err := db.Insert(ctx, table, g.Map{
 				"id":       11,
 				"passport": "never",
@@ -1369,6 +1366,51 @@ func Test_Transaction_Propagation(t *testing.T) {
 	})
 }
 
+func Test_Transaction_Propagation_PropagationSupports(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		table := createTable()
+		defer dropTable(table)
+
+		// scenario1: when in a transaction, use PropagationSupports to execute a transaction
+		err := db.Transaction(ctx, func(ctx context.Context, tx gdb.TX) error {
+			// insert in outer tx.
+			_, err := tx.Insert(table, g.Map{
+				"id": 1,
+			})
+			if err != nil {
+				return err
+			}
+			err = tx.TransactionWithOptions(ctx, gdb.TxOptions{
+				Propagation: gdb.PropagationSupports,
+			}, func(ctx context.Context, tx2 gdb.TX) error {
+				_, err = tx2.Insert(table, g.Map{
+					"id": 2,
+				})
+				return gerror.New("error")
+			})
+			return err
+		})
+		t.AssertNE(err, nil)
+
+		// scenario2: when not in a transaction, do not use transaction but direct db link.
+		err = db.TransactionWithOptions(ctx, gdb.TxOptions{
+			Propagation: gdb.PropagationSupports,
+		}, func(ctx context.Context, tx gdb.TX) error {
+			_, err = tx.Insert(table, g.Map{
+				"id": 3,
+			})
+			return err
+		})
+		t.AssertNil(err)
+
+		// 查询结果
+		result, err := db.Model(table).OrderAsc("id").All()
+		t.AssertNil(err)
+		t.Assert(len(result), 1)
+		t.Assert(result[0]["id"], 3)
+	})
+}
+
 func Test_Transaction_Propagation_Complex(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
 		table1 := createTable()
@@ -1389,7 +1431,7 @@ func Test_Transaction_Propagation_Complex(t *testing.T) {
 			err = tx1.TransactionWithOptions(ctx, gdb.TxOptions{
 				Propagation: gdb.PropagationNested,
 			}, func(ctx context.Context, tx2 gdb.TX) error {
-				_, err := tx2.Insert(table1, g.Map{
+				_, err = tx2.Insert(table1, g.Map{
 					"id":       2,
 					"passport": "nested1",
 				})
@@ -1427,10 +1469,7 @@ func Test_Transaction_Propagation_Complex(t *testing.T) {
 			err = tx1.TransactionWithOptions(ctx, gdb.TxOptions{
 				Propagation: gdb.PropagationNotSupported,
 			}, func(ctx context.Context, tx2 gdb.TX) error {
-				// Should execute without transaction
+				_, err = db.Insert(ctx, table2, g.Map{
-				t.Assert(tx2, nil)
-
-				_, err := db.Insert(ctx, table2, g.Map{
 					"id":       5,
 					"passport": "not_supported",
 				})
@@ -1489,9 +1528,6 @@ func Test_Transaction_Propagation_Complex(t *testing.T) {
 			err = tx1.TransactionWithOptions(ctx, gdb.TxOptions{
 				Propagation: gdb.PropagationNotSupported,
 			}, func(ctx context.Context, tx2 gdb.TX) error {
-				// Should execute without transaction
-				t.Assert(tx2, nil)
-
 				// Start a new independent transaction
 				return db.Transaction(ctx, func(ctx context.Context, tx3 gdb.TX) error {
 					_, err := tx3.Insert(table, g.Map{

database/gdb/gdb_core_transaction.go

@@ -19,9 +19,15 @@ import (
 type Propagation string
 
 const (
+	// PropagationNested starts a nested transaction if already in a transaction,
+	// or behaves like PropagationRequired if not in a transaction.
+	//
+	// It is the default behavior.
+	PropagationNested Propagation = "NESTED"
+
 	// PropagationRequired starts a new transaction if not in a transaction,
 	// or uses the existing transaction if already in a transaction.
-	PropagationRequired Propagation = "" // REQUIRED
+	PropagationRequired Propagation = "REQUIRED"
 
 	// PropagationSupports executes within the existing transaction if present,
 	// otherwise executes without transaction.
@@ -30,10 +36,6 @@ const (
 	// PropagationRequiresNew starts a new transaction, and suspends the current transaction if one exists.
 	PropagationRequiresNew Propagation = "REQUIRES_NEW"
 
-	// PropagationNested starts a nested transaction if already in a transaction,
-	// or behaves like PropagationRequired if not in a transaction.
-	PropagationNested Propagation = "NESTED"
-
 	// PropagationNotSupported executes non-transactional, suspends any existing transaction.
 	PropagationNotSupported Propagation = "NOT_SUPPORTED"
 
@@ -66,7 +68,8 @@ var transactionIdGenerator = gtype.NewUint64()
 // DefaultTxOptions returns the default transaction options.
 func DefaultTxOptions() TxOptions {
 	return TxOptions{
-		Propagation: PropagationRequired,
+		// Note the default propagation type is PropagationNested not PropagationRequired.
+		Propagation: PropagationNested,
 	}
 }
 
@@ -138,11 +141,14 @@ func (c *Core) TransactionWithOptions(
 	switch opts.Propagation {
 	case PropagationRequired:
 		if currentTx != nil {
-			return currentTx.Transaction(ctx, f)
+			return f(ctx, currentTx)
 		}
 		return c.createNewTransaction(ctx, opts, f)
 
 	case PropagationSupports:
+		if currentTx == nil {
+			currentTx = c.newEmptyTX()
+		}
 		return f(ctx, currentTx)
 
 	case PropagationMandatory:
@@ -160,7 +166,7 @@ func (c *Core) TransactionWithOptions(
 
 	case PropagationNotSupported:
 		ctx = WithoutTX(ctx, group)
-		return f(ctx, nil)
+		return f(ctx, c.newEmptyTX())
 
 	case PropagationNever:
 		if currentTx != nil {
@@ -169,22 +175,12 @@ func (c *Core) TransactionWithOptions(
 				"transaction propagation NEVER cannot run within an existing transaction",
 			)
 		}
-		return f(ctx, nil)
+		ctx = WithoutTX(ctx, group)
+		return f(ctx, c.newEmptyTX())
 
 	case PropagationNested:
 		if currentTx != nil {
-			// Create savepoint for nested transaction
+			return currentTx.Transaction(ctx, f)
-			if err = currentTx.Begin(); err != nil {
-				return err
-			}
-			defer func() {
-				if err != nil {
-					if rbErr := currentTx.Rollback(); rbErr != nil {
-						err = gerror.Wrap(err, rbErr.Error())
-					}
-				}
-			}()
-			return f(ctx, currentTx)
 		}
 		return c.createNewTransaction(ctx, opts, f)
 
@@ -280,6 +276,10 @@ func TXFromCtx(ctx context.Context, group string) TX {
 		if tx.IsClosed() {
 			return nil
 		}
+		// no underlying sql tx.
+		if tx.GetSqlTX() == nil {
+			return nil
+		}
 		tx = tx.Ctx(ctx)
 		return tx
 	}

database/gdb/gdb_core_txcore.go

@@ -46,6 +46,12 @@ type TXCore struct {
 	cancelFunc context.CancelFunc
 }
 
+func (c *Core) newEmptyTX() TX {
+	return &TXCore{
+		db: c.db,
+	}
+}
+
 // transactionKeyForNestedPoint forms and returns the transaction key at current save point.
 func (tx *TXCore) transactionKeyForNestedPoint() string {
 	return tx.db.GetCore().QuoteWord(
@@ -427,5 +433,5 @@ func (tx *TXCore) IsOnMaster() bool {
 
 // IsTransaction implements interface function Link.IsTransaction.
 func (tx *TXCore) IsTransaction() bool {
-	return true
+	return tx != nil
 }

database/gdb/gdb_core_underlying.go

@@ -103,7 +103,7 @@ func (c *Core) DoExec(ctx context.Context, link Link, sql string, args ...interf
 			return nil, err
 		}
 	} else if !link.IsTransaction() {
-		// If current link is not transaction link, it checks and retrieves transaction from context.
+		// If current link is not transaction link, it tries retrieving transaction object from context.
 		if tx := TXFromCtx(ctx, c.db.GetGroup()); tx != nil {
 			link = &txLink{tx.GetSqlTX()}
 		}

database/gdb/gdb_model_utility.go

@@ -247,7 +247,9 @@ func (m *Model) doMappingAndFilterForInsertOrUpdateDataMap(data Map, allowOmitEm
 // The parameter `master` specifies whether using the master node if master-slave configured.
 func (m *Model) getLink(master bool) Link {
 	if m.tx != nil {
-		return &txLink{m.tx.GetSqlTX()}
+		if sqlTx := m.tx.GetSqlTX(); sqlTx != nil {
+			return &txLink{sqlTx}
+		}
 	}
 	linkType := m.linkType
 	if linkType == 0 {