add support for mulitple transactions on one session (go-xorm#1015)

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

@@ -128,3 +128,66 @@ func TestCombineTransactionSameMapper(t *testing.T) {
 	err = session.Commit()
 	assert.NoError(t, err)
 }
+
+func TestMultipleTransaction(t *testing.T) {
+	assert.NoError(t, prepareEngine())
+
+	type MultipleTransaction struct {
+		Id   int64
+		Name string
+	}
+
+	assertSync(t, new(MultipleTransaction))
+
+	session := testEngine.NewSession()
+	defer session.Close()
+
+	err := session.Begin()
+	assert.NoError(t, err)
+
+	m1 := MultipleTransaction{Name: "xiaoxiao2"}
+	_, err = session.Insert(&m1)
+	assert.NoError(t, err)
+
+	user2 := MultipleTransaction{Name: "zzz"}
+	_, err = session.Where("id = ?", 0).Update(&user2)
+	assert.NoError(t, err)
+
+	err = session.Commit()
+	assert.NoError(t, err)
+
+	var ms []MultipleTransaction
+	err = session.Find(&ms)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, len(ms))
+
+	err = session.Begin()
+	assert.NoError(t, err)
+
+	_, err = session.Where("id=?", m1.Id).Delete(new(MultipleTransaction))
+	assert.NoError(t, err)
+
+	err = session.Commit()
+	assert.NoError(t, err)
+
+	ms = make([]MultipleTransaction, 0)
+	err = session.Find(&ms)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 0, len(ms))
+
+	err = session.Begin()
+	assert.NoError(t, err)
+
+	_, err = session.Insert(&MultipleTransaction{
+		Name: "ssss",
+	})
+	assert.NoError(t, err)
+
+	err = session.Rollback()
+	assert.NoError(t, err)
+
+	ms = make([]MultipleTransaction, 0)
+	err = session.Find(&ms)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 0, len(ms))
+}