Transaction implementation (#2)

Reviewed-on: #2

dbconnection.go

@@ -36,6 +36,10 @@ func (c *DBConnection) Prepare(sql string) (*sql.Stmt, error) {
 	return c.db.Prepare(sql)
 }
 
+func (c *DBConnection) Begin() (*sql.Tx, error) {
+	return c.db.Begin()
+}
+
 func (c *DBConnection) Close() (bool, error) {
 	err := c.db.Close()
 	if err != nil {

exec/exec.go

@@ -10,6 +10,7 @@ import (
 	log "gitlab.com/gdulai/simpleloglvl"
 )
 
+// Created and executes the DDL created by [simpleorm.ORM]
 func ExecuteDDL(conn *simpleorm.DBConnection, orm *simpleorm.ORM) {
 	schema, err := orm.CreateSchema()
 	if err != nil {
@@ -24,14 +25,143 @@ func ExecuteDDL(conn *simpleorm.DBConnection, orm *simpleorm.ORM) {
 	}
 }
 
+// Wraps and represents a DB transaction.
+// Allows for all at once or separate execution of [exec.Exec] implementations.
+type Transaction struct {
+	conn       *simpleorm.DBConnection
+	executions []*Exec[any]
+	tx         *sql.Tx
+	finished   bool
+}
+
+// Creates a new [exec.Transaction].
+// Can be initialized with a set of [exec.Exec]s.
+func NewTransaction(conn *simpleorm.DBConnection, executions ...*Exec[any]) *Transaction {
+	return &Transaction{conn: conn, executions: executions, finished: false}
+}
+
+// The executions assigned to this transaction.
+func (t *Transaction) Executions() []*Exec[any] {
+	return t.executions
+}
+
+// Executes all the [exec.Exec] implementations assigned to this transactions.
+// Begins, commits or rollbacks the transaction.
+// This is a terminal operation, the [exec.Transaction] is considered finished after calling this.
+func (t *Transaction) ExecuteAtOnce() error {
+	if t.finished {
+		return errors.New("Transaction already finished.")
+	}
+
+	if t.tx == nil {
+		tx, err := t.conn.Begin()
+		t.tx = tx
+		if err != nil {
+			t.finished = true
+			return err
+		}
+	}
+
+	for _, exec := range t.executions {
+		err := (*exec).execute(nil, t.tx)
+		if err != nil {
+			rollbackErr := t.Rollback()
+			if rollbackErr != nil {
+				return rollbackErr
+			}
+			return err
+		}
+
+	}
+
+	err := t.tx.Commit()
+	if err != nil {
+		return err
+	}
+
+	t.finished = true
+	return nil
+}
+
+// Executes and assigns the passed [exec.Exec]s to the Transaction.
+// Calls rollback in case of an error.
+// This is NOT a terminal operation, transactions still has to be committed.
+func (t *Transaction) Execute(execs ...Exec[any]) error {
+	if t.finished {
+		return errors.New("Transaction already finished.")
+	}
+
+	for _, exec := range execs {
+		execPtr := &exec
+		t.executions = append(t.executions, execPtr)
+		if t.tx == nil {
+			tx, err := t.conn.Begin()
+			t.tx = tx
+			if err != nil {
+				t.finished = true
+				return err
+			}
+		}
+
+		err := (*execPtr).execute(nil, t.tx)
+		if err != nil {
+			rollbackErr := t.Rollback()
+			if rollbackErr != nil {
+				return rollbackErr
+			}
+			return err
+		}
+
+	}
+
+	return nil
+}
+
+// Finishes the transaction, commits the changes.
+// This is terminal operation.
+func (t *Transaction) Finish() error {
+	if t.finished {
+		return errors.New("Transaction already finished.")
+	}
+
+	if t.tx == nil {
+		return errors.New("Transaction is nil.")
+	}
+
+	t.tx.Commit()
+	t.finished = true
+	return nil
+}
+
+// Rollbacks and aborts the transaction.
+// This is a terminal operation.
+func (t *Transaction) Rollback() error {
+	if t.finished {
+		return errors.New("Transaction already finished.")
+	}
+
+	if t.tx == nil {
+		return errors.New("Transaction is nil.")
+	}
+
+	rollbackErr := t.tx.Rollback()
+	if rollbackErr != nil {
+		return rollbackErr
+	}
+	t.finished = true
+	return nil
+}
+
 type Exec[T any] interface {
-	Execute(conn *simpleorm.DBConnection) ([]T, error)
+	Execute(conn *simpleorm.DBConnection) error
+	execute(conn *simpleorm.DBConnection, tx *sql.Tx) error
 }
 
 type Select[T any] struct {
 	target    schema.Table
 	whereStmt string
 	args      []any
+	results   []T
 }
 
 func CreateSelect[T any](orm *simpleorm.ORM, whereStmt string, args ...any) (Select[T], error) {
@@ -43,10 +173,20 @@ func CreateSelect[T any](orm *simpleorm.ORM, whereStmt string, args ...any) (Sel
 	return Select[T]{target: *table, whereStmt: whereStmt, args: args}, nil
 }
 
-func (s Select[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
+func (s *Select[T]) Results() []T {
+	return s.results
+}
+
+func (s *Select[T]) Execute(conn *simpleorm.DBConnection) error {
+	return s.execute(conn, nil)
+}
+
+func (s *Select[T]) execute(conn *simpleorm.DBConnection, tx *sql.Tx) error {
+	// Reinit the results, new execution
+	s.results = []T{}
 	dml, err := s.target.GetSelectDML()
 	if err != nil {
-		return []T{}, err
+		return err
 	}
 
 	if s.whereStmt != "" {
@@ -55,9 +195,15 @@ func (s Select[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 
 	log.LogDebug("Preparing sql: %s, with args: %s", dml, s.args)
 
-	stmt, err := conn.Prepare(dml)
+	var stmt *sql.Stmt
+	if tx != nil {
+		stmt, err = tx.Prepare(dml)
+	} else {
+		stmt, err = conn.Prepare(dml)
+	}
+
 	if err != nil {
-		return nil, err
+		return err
 	}
 	defer stmt.Close()
 
@@ -81,40 +227,21 @@ func (s Select[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 	}
 
 	if err != nil {
-		return nil, err
+		return err
 	}
 
-	rowContainer := createSelectResultContainer(s.target)
-
-	var results []T
-
-	for rows.Next() {
-		err = rows.Scan(rowContainer...)
-		if err != nil {
-			return nil, err
-		}
-
-		targetType := s.target.Type
-		parsedResult := reflect.New(targetType)
-		for i, fieldVal := range rowContainer {
-			col := s.target.Columns[i]
-			targetField := parsedResult.Elem().Field(i)
-
-			rawValue := reflect.Indirect(reflect.ValueOf(fieldVal))
-			decoded := reflect.ValueOf(col.Decode(targetField.Type().Name(), rawValue))
-
-			targetField.Set(decoded)
-		}
-		parsedObj := reflect.Indirect(parsedResult).Interface().(T)
-		results = append(results, parsedObj)
+	s.results, err = readRows[T](s.target, rows)
+	if err != nil {
+		return err
 	}
 
-	return results, nil
+	return nil
 }
 
 type Insert[T any] struct {
 	target   schema.Table
 	toInsert []T
+	results  []T
 }
 
 func NewInsert[T any](orm *simpleorm.ORM, toInsert ...T) (Insert[T], error) {
@@ -126,10 +253,18 @@ func NewInsert[T any](orm *simpleorm.ORM, toInsert ...T) (Insert[T], error) {
 	return Insert[T]{target: *table, toInsert: toInsert}, nil
 }
 
-func (ins Insert[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
+func (ins *Insert[T]) Results() []T {
+	return ins.results
+}
+
+func (ins *Insert[T]) Execute(conn *simpleorm.DBConnection) error {
+	return ins.execute(conn, nil)
+}
+
+func (ins *Insert[T]) execute(conn *simpleorm.DBConnection, tx *sql.Tx) error {
 	dml, err := ins.target.GetInsertDML(len(ins.toInsert))
 	if err != nil {
-		return []T{}, err
+		return err
 	}
 
 	var params []any
@@ -145,21 +280,26 @@ func (ins Insert[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 
 	log.LogInfo("%s [%s]", dml, params)
 
-	stmt, err := conn.Prepare(dml)
-	if err != nil {
-		return []T{}, err
+	var stmt *sql.Stmt
+	if tx != nil {
+		stmt, err = tx.Prepare(dml)
+	} else {
+		stmt, err = conn.Prepare(dml)
 	}
 	defer stmt.Close()
 
-	result, err := stmt.Exec(params...)
+	rows, err := stmt.Query(params...)
+
 	if err != nil {
-	} else {
-		rowsAffected, _ := result.RowsAffected()
-		log.LogInfo("Inserted %s row", rowsAffected)
-		lastInsertId, _ := result.LastInsertId()
-		log.LogInfo("Last ID: %s", lastInsertId)
+		return err
 	}
-	return []T{}, nil
+
+	ins.results, err = readRows[T](ins.target, rows)
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 type Update[T any] struct {
@@ -176,17 +316,21 @@ func NewUpdate[T any](orm *simpleorm.ORM, toUpdate T) (Update[T], error) {
 	return Update[T]{target: *table, toUpdate: toUpdate}, nil
 }
 
-func (u Update[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
+func (u Update[T]) Execute(conn *simpleorm.DBConnection) error {
+	return u.execute(conn, nil)
+}
+
+func (u Update[T]) execute(conn *simpleorm.DBConnection, tx *sql.Tx) error {
 	dml, err := u.target.GetUpdateDML()
 	if err != nil {
-		return []T{}, err
+		return err
 	}
 
 	params := prepareParams(u.toUpdate, u.target)
 
 	pkCols, err := getPk(u.toUpdate, u.target)
 	if err != nil {
-		return []T{}, err
+		return err
 	}
 	// Put the pks back at the end
 	for _, pk := range pkCols {
@@ -195,20 +339,22 @@ func (u Update[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 
 	log.LogInfo("%s [%s]", dml, params)
 
-	stmt, err := conn.Prepare(dml)
-	if err != nil {
-		return []T{}, err
+	var stmt *sql.Stmt
+	if tx != nil {
+		stmt, err = tx.Prepare(dml)
+	} else {
+		stmt, err = conn.Prepare(dml)
 	}
 	defer stmt.Close()
 
 	result, err := stmt.Exec(params...)
 	if err != nil {
-		return []T{}, err
+		return err
 	} else {
 		rowsAffected, _ := result.RowsAffected()
 		log.LogInfo("Updated %s row", rowsAffected)
 	}
-	return []T{u.toUpdate}, nil
+	return nil
 }
 
 type Delete[T any] struct {
@@ -225,11 +371,15 @@ func NewDelete[T any](orm *simpleorm.ORM, toDelete []T) (Delete[T], error) {
 	return Delete[T]{target: *table, toDelete: toDelete}, nil
 }
 
-func (d Delete[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
+func (d *Delete[T]) Execute(conn *simpleorm.DBConnection) error {
+	return d.execute(conn, nil)
+}
+
+func (d *Delete[T]) execute(conn *simpleorm.DBConnection, tx *sql.Tx) error {
 	count := len(d.toDelete)
 	dml, err := d.target.GetDeleteDML(count)
 	if err != nil {
-		return []T{}, err
+		return err
 	}
 
 	var params []any
@@ -237,7 +387,7 @@ func (d Delete[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 	for _, del := range d.toDelete {
 		pkCols, err := getPk(del, d.target)
 		if err != nil {
-			return []T{}, err
+			return err
 		}
 
 		for _, pk := range pkCols {
@@ -247,21 +397,23 @@ func (d Delete[T]) Execute(conn *simpleorm.DBConnection) ([]T, error) {
 
 	log.LogInfo("%s [%s]", dml, params)
 
-	stmt, err := conn.Prepare(dml)
-	if err != nil {
-		return []T{}, err
+	var stmt *sql.Stmt
+	if tx != nil {
+		stmt, err = tx.Prepare(dml)
+	} else {
+		stmt, err = conn.Prepare(dml)
 	}
 	defer stmt.Close()
 
 	result, err := stmt.Exec(params...)
 	if err != nil {
-		return []T{}, err
+		return err
 	} else {
 		rowsAffected, _ := result.RowsAffected()
 		log.LogInfo("Deleted %s row", rowsAffected)
 	}
 
-	return d.toDelete, nil
+	return nil
 
 }
 
@@ -322,3 +474,31 @@ func getPk(src any, t schema.Table) ([]any, error) {
 
 	return values, nil
 }
+
+func readRows[T any](table schema.Table, rows *sql.Rows) ([]T, error) {
+	rowContainer := createSelectResultContainer(table)
+
+	var results []T
+
+	for rows.Next() {
+		err := rows.Scan(rowContainer...)
+		if err != nil {
+			return nil, err
+		}
+
+		targetType := table.Type
+		parsedResult := reflect.New(targetType)
+		for i, fieldVal := range rowContainer {
+			col := table.Columns[i]
+			targetField := parsedResult.Elem().Field(i)
+
+			rawValue := reflect.Indirect(reflect.ValueOf(fieldVal))
+			decoded := reflect.ValueOf(col.Decode(targetField.Type().Name(), rawValue))
+
+			targetField.Set(decoded)
+		}
+		parsedObj := reflect.Indirect(parsedResult).Interface().(T)
+		results = append(results, parsedObj)
+	}
+	return results, nil
+}

repository/repository.go

@@ -29,15 +29,16 @@ func (r *Repository[T]) SelectAll() []*T {
 		return []*T{}
 	}
 
-	selecRes, err := selectExec.Execute(r.conn)
+	err = selectExec.Execute(r.conn)
 	if err != nil {
 		log.LogError("Failed to load projects: %s", err)
 		return []*T{}
 	}
 
-	res := make([]*T, 0, len(selecRes))
-	for i := range selecRes {
-		res = append(res, &selecRes[i])
+	selectRes := selectExec.Results()
+	res := make([]*T, 0, len(selectRes))
+	for i := range selectRes {
+		res = append(res, &selectRes[i])
 	}
 
 	return res
@@ -73,55 +74,57 @@ func (r *Repository[T]) SelectByPk(pks ...any) *T {
 		return nil
 	}
 
-	res, err := selectExec.Execute(r.conn)
+	err = selectExec.Execute(r.conn)
 	if err != nil {
 		log.LogError("Failed to load entity: %s", err)
 		return nil
 	}
-
-	if len(res) != 1 {
-		log.LogError("Invalid result number of results: %s", len(res))
+	selectRes := selectExec.Results()
+	if len(selectRes) != 1 {
+		log.LogError("Invalid result number of results: %s", len(selectRes))
 		return nil
 	}
 
-	return &res[0]
+	return &selectRes[0]
 }
 
-func (r *Repository[T]) Save(entity T) {
+func (r *Repository[T]) Save(entity *T) error {
 	// Insert
-	if entity.IsInsertable() {
-		insertExec, err := exec.NewInsert[T](r.orm, entity)
+	if (*entity).IsInsertable() {
+		insertExec, err := exec.NewInsert[T](r.orm, *entity)
 		if err != nil {
-			log.LogError("Failed to create insert execution: %s", err)
-			return
+			return err
 		}
-		if _, err := insertExec.Execute(r.conn); err != nil {
-			log.LogError("Insert failed for entity: %s", entity)
+		err = insertExec.Execute(r.conn)
+		if err != nil {
+			return err
 		}
-
-		return
+		result := insertExec.Results()
+		// Point to the new inserted result
+		*entity = result[0]
+		return nil
 	}
 
-	updateExec, err := exec.NewUpdate[T](r.orm, entity)
+	updateExec, err := exec.NewUpdate[T](r.orm, *entity)
 	if err != nil {
-		log.LogError("Failed to create update execution: %s", err)
-		return
+		return err
 	}
 
-	_, err = updateExec.Execute(r.conn)
+	err = updateExec.Execute(r.conn)
 	if err != nil {
-		log.LogError("Update failed: %s", err)
-		return
+		return err
 	}
+
+	return nil
 }
 
-func (r *Repository[T]) Delete(entity T) {
-	deleteExec, err := exec.NewDelete[T](r.orm, []T{entity})
+func (r *Repository[T]) Delete(entity *T) {
+	deleteExec, err := exec.NewDelete[T](r.orm, []T{*entity})
 	if err != nil {
 		log.LogError("Failed to create delete execution: %s", err)
 		return
 	}
-	_, err = deleteExec.Execute(r.conn)
+	err = deleteExec.Execute(r.conn)
 	if err != nil {
 		log.LogError("Delete failed: %s", err)
 		return

schema/table.go

@@ -100,6 +100,8 @@ func (t Table) GetInsertDML(count int) (string, error) {
 		}
 	}
 
+	dml.WriteString("RETURNING *")
+
 	return dml.String(), nil
 }
 

test/exec_test.go

@@ -1,48 +1,36 @@
 package simpleorm_test
 
 import (
-	"os"
 	"testing"
 	"time"
 
-	simpleorm "git.gdulai.com/gdulai/simpleorm"
 	"git.gdulai.com/gdulai/simpleorm/exec"
 	log "gitlab.com/gdulai/simpleloglvl"
 )
 
-func cleanUp(dbFile string, conn *simpleorm.DBConnection) {
-	conn.Close()
-	os.Remove(dbFile)
-}
-
 func TestSelectEmpty(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
-
 	// WHEN
 	selectExec, err := exec.CreateSelect[Test](orm, "")
 
 	// THEN
-
 	if err != nil {
 		log.LogError("Failed to create select. %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
-
+	err = selectExec.Execute(conn)
 	if err != nil {
 		log.LogError("Select failure. %s", err)
 		t.Fail()
 		return
 	}
+
+	res := selectExec.Results()
 	if len(res) > 0 {
 		log.LogError("Expected empty result.")
 		t.Fail()
@@ -50,17 +38,108 @@ func TestSelectEmpty(t *testing.T) {
 	}
 }
 
-func TestInsertAndSelectSingle(t *testing.T) {
+func TestInsert(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 
+	// WHEN
+	insertExec, err := exec.NewInsert(orm, testObj)
+	if err != nil {
+		log.LogError("TestInsertAndSelectSingle setup failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	insertErr := insertExec.Execute(conn)
+	if err != nil {
+		log.LogError("TestInsertAndSelectSingle insert failed: %s", err)
+		t.Fail()
+		return
+	}
+	insertRes := insertExec.Results()
+
+	// THEN
+	if insertErr != nil {
+		log.LogError("TestInsertAndSelectSingle failure. %s", err)
+		t.Fail()
+		return
+	}
+
+	if len(insertRes) != 1 {
+		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(insertRes))
+		t.Fail()
+		return
+	}
+
+	singleRes := insertRes[0]
+	if singleRes.ID != 1 || singleRes.Int64Field != 54 || singleRes.IntField != 12 || singleRes.StringField != "asdf" {
+		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObj, singleRes)
+		t.Fail()
+	}
+}
+
+func TestInsertMultiple(t *testing.T) {
+	// GIVEN
+	orm, conn := testSetup()
+	defer cleanUp("test.db", conn)
+
+	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+	testObjSecond := Test{Int64Field: 12, IntField: 54, StringField: "fdsa"}
+
+	// WHEN
+	insertExec, err := exec.NewInsert[Test](orm, testObj, testObjSecond)
+	if err != nil {
+		log.LogError("TestInsertAndSelectSingle setup failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	insertErr := insertExec.Execute(conn)
+	if err != nil {
+		log.LogError("TestInsertAndSelectSingle insert failed: %s", err)
+		t.Fail()
+		return
+	}
+	insertRes := insertExec.Results()
+
+	// THEN
+	if insertErr != nil {
+		log.LogError("TestInsertAndSelectSingle failure. %s", err)
+		t.Fail()
+		return
+	}
+
+	if len(insertRes) != 2 {
+		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(insertRes))
+		t.Fail()
+		return
+	}
+
+	entity := insertRes[0]
+	if entity.ID != 1 || entity.Int64Field != 54 || entity.IntField != 12 || entity.StringField != "asdf" {
+		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObj, entity)
+		t.Fail()
+	}
+
+	entity = insertRes[1]
+	if entity.ID != 2 || entity.Int64Field != 12 || entity.IntField != 54 || entity.StringField != "fdsa" {
+		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObjSecond, entity)
+		t.Fail()
+	}
+
+}
+
+func TestInsertAndSelectSingle(t *testing.T) {
+	// GIVEN
+	orm, conn := testSetup()
+	defer cleanUp("test.db", conn)
+
+	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestInsertAndSelectSingle setup failed: %s", err)
@@ -75,29 +154,43 @@ func TestInsertAndSelectSingle(t *testing.T) {
 		return
 	}
 
-	// WHEN
-	_, err = insertExec.Execute(conn)
-	if err != nil {
+	insertErr := insertExec.Execute(conn)
+	selectErr := selectExec.Execute(conn)
+
+	// THEN
+	if insertErr != nil {
 		log.LogError("TestInsertAndSelectSingle insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
-
-	// THEN
-	if err != nil {
+	if selectErr != nil {
 		log.LogError("TestInsertAndSelectSingle failure. %s", err)
 		t.Fail()
 		return
 	}
-	if len(res) != 1 {
-		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(res))
+
+	insertRes := insertExec.Results()
+	if len(insertRes) != 1 {
+		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(insertRes))
 		t.Fail()
 		return
 	}
 
-	singleRes := res[0]
+	selectRes := selectExec.Results()
+	if len(selectRes) != 1 {
+		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(selectRes))
+		t.Fail()
+		return
+	}
+
+	singleRes := insertRes[0]
+	if singleRes.ID != 1 || singleRes.Int64Field != 54 || singleRes.IntField != 12 || singleRes.StringField != "asdf" {
+		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObj, singleRes)
+		t.Fail()
+	}
+
+	singleRes = selectRes[0]
 	if singleRes.ID != 1 || singleRes.Int64Field != 54 || singleRes.IntField != 12 || singleRes.StringField != "asdf" {
 		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObj, singleRes)
 		t.Fail()
@@ -107,15 +200,12 @@ func TestInsertAndSelectSingle(t *testing.T) {
 
 func TestInsertSelectWithCompositePk(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	testObj := TestWithCompositePk{ID: 12, Name: "Test"}
 
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestInsertSelectWithCompositePk setup failed: %s", err)
@@ -130,15 +220,14 @@ func TestInsertSelectWithCompositePk(t *testing.T) {
 		return
 	}
 
-	// WHEN
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertSelectWithCompositePk insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -146,6 +235,8 @@ func TestInsertSelectWithCompositePk(t *testing.T) {
 		t.Fail()
 		return
 	}
+
+	res := selectExec.Results()
 	if len(res) != 1 {
 		log.LogError("TestInsertSelectWithCompositePk test failed. Expected: 1, Actual: %s", len(res))
 		t.Fail()
@@ -162,14 +253,10 @@ func TestInsertSelectWithCompositePk(t *testing.T) {
 
 func TestInsertMultipleAndSelectWithParam(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
-
+	// WHEN
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 	testObjSecond := Test{Int64Field: 12, IntField: 54, StringField: "fdsa"}
 
@@ -194,23 +281,21 @@ func TestInsertMultipleAndSelectWithParam(t *testing.T) {
 		return
 	}
 
-	// WHEN
-
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertMultipleAndSelectWithParam first insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	_, err = insertSecond.Execute(conn)
+	err = insertSecond.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertMultipleAndSelectWithParam second insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -218,6 +303,8 @@ func TestInsertMultipleAndSelectWithParam(t *testing.T) {
 		t.Fail()
 		return
 	}
+
+	res := selectExec.Results()
 	if len(res) != 1 {
 		log.LogError(" TestInsertMultipleAndSelectWithParam test failed. Expected: 1, Actual: %s", len(res))
 		t.Fail()
@@ -234,15 +321,12 @@ func TestInsertMultipleAndSelectWithParam(t *testing.T) {
 
 func TestInsertAndUpdate(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestInsertAndUpdate setup failed: %s", err)
@@ -257,22 +341,21 @@ func TestInsertAndUpdate(t *testing.T) {
 		return
 	}
 
-	// WHEN
-
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertAndUpdate insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertAndUpdate re-select failed: %s", err)
 		t.Fail()
 		return
 	}
 
+	res := selectExec.Results()
 	testObj = res[0]
 
 	testObj.IntField = 42069
@@ -285,8 +368,8 @@ func TestInsertAndUpdate(t *testing.T) {
 		return
 	}
 
-	_, err = updateExec.Execute(conn)
-	res, selectErr := selectExec.Execute(conn)
+	err = updateExec.Execute(conn)
+	selectErr := selectExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -301,6 +384,7 @@ func TestInsertAndUpdate(t *testing.T) {
 		return
 	}
 
+	res = selectExec.Results()
 	if len(res) != 1 {
 		log.LogError("TestInsertAndUpdate test failed. Expected: 1, Actual: %s", len(res))
 		t.Fail()
@@ -317,15 +401,12 @@ func TestInsertAndUpdate(t *testing.T) {
 
 func TestInsertAndDelete(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestInsertAndDelete setup failed: %s", err)
@@ -333,7 +414,7 @@ func TestInsertAndDelete(t *testing.T) {
 		return
 	}
 
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertAndDelete setup failed: %s", err)
 		t.Fail()
@@ -347,18 +428,15 @@ func TestInsertAndDelete(t *testing.T) {
 		return
 	}
 
-	selectRes, err := selectExec.Execute(conn)
-
+	err = selectExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestInsertAndDelete setup failed. %s", err)
 		t.Fail()
 		return
 	}
 
-	deleteExec, err := exec.NewDelete(orm, selectRes)
-
-	// WHEN
-	_, err = deleteExec.Execute(conn)
+	deleteExec, err := exec.NewDelete(orm, selectExec.Results())
+	err = deleteExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -367,7 +445,15 @@ func TestInsertAndDelete(t *testing.T) {
 		return
 	}
 
-	selectRes, err = selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
+	// THEN
+	if err != nil {
+		log.LogError("TestInsertAndDelete delete failure. %s", err)
+		t.Fail()
+		return
+	}
+
+	selectRes := selectExec.Results()
 	if len(selectRes) != 0 {
 		log.LogError("TestInsertAndDelete test failed. Expected: 0, Actual: %s", len(selectRes))
 		t.Fail()
@@ -378,14 +464,12 @@ func TestInsertAndDelete(t *testing.T) {
 
 func TestBoolInsertAndSelectSingle(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(TestWithBool{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	testObj := TestWithBool{BoolField: true}
 
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestBoolInsertAndSelectSingle setup failed: %s", err)
@@ -400,15 +484,14 @@ func TestBoolInsertAndSelectSingle(t *testing.T) {
 		return
 	}
 
-	// WHEN
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestBoolInsertAndSelectSingle insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -416,6 +499,8 @@ func TestBoolInsertAndSelectSingle(t *testing.T) {
 		t.Fail()
 		return
 	}
+
+	res := selectExec.Results()
 	if len(res) != 1 {
 		log.LogError("TestBoolInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(res))
 		t.Fail()
@@ -432,15 +517,13 @@ func TestBoolInsertAndSelectSingle(t *testing.T) {
 
 func TestTimeInsertAndSelectSingle(t *testing.T) {
 	// GIVEN
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
-	orm := simpleorm.NewORM(TestWithTime{})
-
-	exec.ExecuteDDL(conn, orm)
 
 	now := time.Now().UnixMilli()
 	testObj := TestWithTime{TimeField: now}
 
+	// WHEN
 	insertExec, err := exec.NewInsert(orm, testObj)
 	if err != nil {
 		log.LogError("TestTimeInsertAndSelectSingle setup failed: %s", err)
@@ -455,15 +538,14 @@ func TestTimeInsertAndSelectSingle(t *testing.T) {
 		return
 	}
 
-	// WHEN
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	if err != nil {
 		log.LogError("TestTimeInsertAndSelectSingle insert failed: %s", err)
 		t.Fail()
 		return
 	}
 
-	res, err := selectExec.Execute(conn)
+	err = selectExec.Execute(conn)
 
 	// THEN
 	if err != nil {
@@ -471,6 +553,8 @@ func TestTimeInsertAndSelectSingle(t *testing.T) {
 		t.Fail()
 		return
 	}
+
+	res := selectExec.Results()
 	if len(res) != 1 {
 		log.LogError("TestTimeInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(res))
 		t.Fail()
@@ -484,3 +568,116 @@ func TestTimeInsertAndSelectSingle(t *testing.T) {
 	}
 
 }
+
+func TestTransactionExecuteSimple(t *testing.T) {
+	// GIVEN
+	orm, conn := testSetup()
+	defer cleanUp("test.db", conn)
+
+	transaction := exec.NewTransaction(conn)
+
+	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+
+	// WHEN
+	insertExec, err := exec.NewInsert[Test](orm, testObj)
+	if err != nil {
+		log.LogError("TestTransactionExecuteSimple failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	transErr := transaction.Execute(&insertExec)
+	if transErr != nil {
+		transErr = transaction.Finish()
+	}
+
+	// THEN
+	if transErr != nil {
+		log.LogError("TestTransactionExecuteSimple failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	insertRes := insertExec.Results()
+
+	if len(insertRes) != 1 {
+		log.LogError("TestInsertAndSelectSingle test failed. Expected: 1, Actual: %s", len(insertRes))
+		t.Fail()
+		return
+	}
+
+	singleRes := insertRes[0]
+	if singleRes.ID != 1 || singleRes.Int64Field != 54 || singleRes.IntField != 12 || singleRes.StringField != "asdf" {
+		log.LogError("TestInsertAndSelectSingle invalid result. Expected: %s, Actual: %s", testObj, singleRes)
+		t.Fail()
+	}
+}
+
+func TestTransactionRollback(t *testing.T) {
+	// GIVEN
+	orm, conn := testSetup()
+	defer cleanUp("test.db", conn)
+
+	transaction := exec.NewTransaction(conn)
+
+	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+
+	// WHEN
+	insertExec, err := exec.NewInsert[Test](orm, testObj)
+	if err != nil {
+		log.LogError("TestTransactionRollback WHEN failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	transErr := transaction.Execute(&insertExec)
+	if transErr != nil {
+		log.LogError("TestTransactionRollback WHEN failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	selectExec, err := exec.CreateSelect[Test](orm, "id = ?", insertExec.Results()[0].ID)
+	if err != nil {
+		log.LogError("TestTransactionRollback WHEN failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	transErr = transaction.Execute(&selectExec)
+	if transErr != nil {
+		log.LogError("TestTransactionRollback WHEN failed: %s", err)
+		t.Fail()
+		return
+	}
+
+	beforeRollbackSelectRes := selectExec.Results()
+	rollbackErr := transaction.Rollback()
+	afterRollbackErr := selectExec.Execute(conn)
+	afterRollbackSelectRes := selectExec.Results()
+
+	// THEN
+	if len(beforeRollbackSelectRes) != 1 {
+		log.LogError("TestTransactionExecuteSimple-THEN: Expected 1, Actual: %s", len(beforeRollbackSelectRes))
+		t.Fail()
+		return
+	}
+
+	if rollbackErr != nil {
+		log.LogError("TestTransactionExecuteSimple-THEN: rollback error: %s", rollbackErr)
+		t.Fail()
+		return
+	}
+
+	if afterRollbackErr != nil {
+		log.LogError("TestTransactionExecuteSimple-THEN: after rollback select error: %s", rollbackErr)
+		t.Fail()
+		return
+	}
+
+	if len(afterRollbackSelectRes) != 0 {
+		log.LogError("TestTransactionExecuteSimple-THEN: Expected 0 after rollback select result")
+		t.Fail()
+		return
+	}
+}

test/main_test.go

@@ -4,6 +4,8 @@ import (
 	"os"
 	"testing"
 
+	simpleorm "git.gdulai.com/gdulai/simpleorm"
+	"git.gdulai.com/gdulai/simpleorm/exec"
 	_ "github.com/mattn/go-sqlite3"
 	log "gitlab.com/gdulai/simpleloglvl"
 )
@@ -61,3 +63,18 @@ func TestMain(m *testing.M) {
 
 	os.Exit(code)
 }
+
+func testSetup() (*simpleorm.ORM, *simpleorm.DBConnection) {
+	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
+
+	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
+		TestWithCompositePk{}, TestWithCompositeFk{}, TestWithBool{}, TestWithTime{})
+	exec.ExecuteDDL(conn, orm)
+
+	return orm, conn
+}
+
+func cleanUp(dbFile string, conn *simpleorm.DBConnection) {
+	conn.Close()
+	os.Remove(dbFile)
+}

test/repository_test.go

@@ -3,26 +3,14 @@ package simpleorm_test
 import (
 	"testing"
 
-	simpleorm "git.gdulai.com/gdulai/simpleorm"
 	"git.gdulai.com/gdulai/simpleorm/exec"
 	"git.gdulai.com/gdulai/simpleorm/repository"
 	log "gitlab.com/gdulai/simpleloglvl"
 )
 
-func repoTestSetup() (*simpleorm.ORM, *simpleorm.DBConnection) {
-	conn := simpleorm.OpenConnection("sqlite3", "file:test.db")
-
-	orm := simpleorm.NewORM(Test{}, TestWithFk{}, TestWithFkAndFkId{},
-		TestWithCompositePk{}, TestWithCompositeFk{})
-
-	exec.ExecuteDDL(conn, orm)
-
-	return orm, conn
-}
-
 func TestRepoSelectAll(t *testing.T) {
 	// GIVEN
-	orm, conn := repoTestSetup()
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
@@ -32,7 +20,7 @@ func TestRepoSelectAll(t *testing.T) {
 		t.Fail()
 		return
 	}
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	repo := repository.NewRepository[Test](conn, orm)
 
 	// WHEN
@@ -48,7 +36,7 @@ func TestRepoSelectAll(t *testing.T) {
 
 func TestRepoSelectByPk(t *testing.T) {
 	// GIVEN
-	orm, conn := repoTestSetup()
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
 	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
@@ -58,7 +46,7 @@ func TestRepoSelectByPk(t *testing.T) {
 		t.Fail()
 		return
 	}
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	repo := repository.NewRepository[Test](conn, orm)
 
 	// WHEN
@@ -74,7 +62,7 @@ func TestRepoSelectByPk(t *testing.T) {
 
 func TestRepoSelectByCompundPk(t *testing.T) {
 	// GIVEN
-	orm, conn := repoTestSetup()
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
 	testObj := TestWithCompositePk{ID: 42069, Name: "Test"}
@@ -84,7 +72,7 @@ func TestRepoSelectByCompundPk(t *testing.T) {
 		t.Fail()
 		return
 	}
-	_, err = insertExec.Execute(conn)
+	err = insertExec.Execute(conn)
 	repo := repository.NewRepository[TestWithCompositePk](conn, orm)
 
 	// WHEN
@@ -100,46 +88,45 @@ func TestRepoSelectByCompundPk(t *testing.T) {
 
 func TestRepoSave(t *testing.T) {
 	// GIVEN
-	orm, conn := repoTestSetup()
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
-	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+	testObj := &Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 	repo := repository.NewRepository[Test](conn, orm)
 
 	// WHEN
-	repo.Save(testObj)
+	err := repo.Save(testObj)
 
 	// THEN
-	res := repo.SelectByPk(1)
-	if res == nil {
-		log.LogError("TestRepoSave test failed. Result is nil!")
+	if err != nil {
+		log.LogError("TestRepoSave failed: %s", err)
+	}
+	if testObj.ID == 0 {
+		log.LogError("TestRepoSave failed! testObj.ID is 0!")
 		t.Fail()
-		return
 	}
 }
 
 func TestRepoDelete(t *testing.T) {
 	// GIVEN
-	orm, conn := repoTestSetup()
+	orm, conn := testSetup()
 	defer cleanUp("test.db", conn)
 
-	testObj := Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
+	testObj := &Test{Int64Field: 54, IntField: 12, StringField: "asdf"}
 	repo := repository.NewRepository[Test](conn, orm)
 
-	repo.Save(testObj)
-
-	res := repo.SelectByPk(1)
-	if res == nil {
+	err := repo.Save(testObj)
+	if err != nil {
 		log.LogError("TestRepoDelete setup failed! Test data not saved!")
 		t.Fail()
 		return
 	}
 
 	// WHEN
-	repo.Delete(*res)
+	repo.Delete(testObj)
 
 	// THEN
-	res = repo.SelectByPk(1)
+	res := repo.SelectByPk(testObj.ID)
 	if res != nil {
 		log.LogError("TestRepoDelete test failed. Result is not nil!")
 		t.Fail()