support reuse session to transaction (#650)

session_tx.go

@@ -24,6 +24,7 @@ func (session *Session) Rollback() error {
 	if !session.IsAutoCommit && !session.IsCommitedOrRollbacked {
 		session.saveLastSQL(session.Engine.dialect.RollBackStr())
 		session.IsCommitedOrRollbacked = true
+		session.IsAutoCommit = true
 		return session.Tx.Rollback()
 	}
 	return nil
@@ -34,6 +35,7 @@ func (session *Session) Commit() error {
 	if !session.IsAutoCommit && !session.IsCommitedOrRollbacked {
 		session.saveLastSQL("COMMIT")
 		session.IsCommitedOrRollbacked = true
+		session.IsAutoCommit = true
 		var err error
 		if err = session.Tx.Commit(); err == nil {
 			// handle processors after tx committed

session_tx_test.go

@@ -190,3 +190,34 @@ func TestCombineTransactionSameMapper(t *testing.T) {
 		panic(err)
 	}
 }
+
+func TestReuseTransaction(t *testing.T) {
+	assert.NoError(t, prepareEngine())
+	sess := testEngine.NewSession()
+	defer sess.Close()
+
+	type ReuseTx struct {
+		Id   int64
+		Name string
+	}
+
+	assertSync(t, new(ReuseTx))
+
+	records := []ReuseTx{
+		{
+			Name: "1",
+		},
+		{
+			Name: "3",
+		},
+		{
+			Name: "2",
+		},
+	}
+	for _, r := range records {
+		assert.NoError(t, sess.Begin())
+		_, err := sess.Insert(&r)
+		assert.NoError(t, err)
+		assert.NoError(t, sess.Commit())
+	}
+}