Add Transaction Support

README.md

@@ -9,6 +9,7 @@ Yet Another ORM library for Go, aims for developer friendly
 * Callbacks (before/after create/save/update/delete)
 * Soft Delete
 * Auto Migration
+* Transaction
 * Every feature comes with tests
 * Convention Over Configuration
 * Developer Friendly
@@ -617,6 +618,24 @@ func (u User) TableName() string {
 }
 ```
 
+## Transaction
+
+```go
+tx := db.Begin()
+
+user := User{Name: "transcation"}
+
+tx.Save(&u)
+tx.Update("age": 90)
+// do whatever
+
+// rollback
+tx.Rollback()
+
+// commit
+tx.Commit()
+```
+
 ## Run Raw SQl
 
 ```go
@@ -668,7 +687,6 @@ db.Where("email = ?", "x@example.org").Attrs(User{FromIp: "111.111.111.111"}).Fi
 ```
 
 ## TODO
-* Transaction
 * Logger
 * Join, Having, Group
 * Index, Unique, Valiations

chain.go

@@ -1,14 +1,13 @@
 package gorm
 
 import (
-	"database/sql"
 	"errors"
 	"fmt"
 	"regexp"
 )
 
 type Chain struct {
-	db     *sql.DB
+	db     sql_common
 	driver string
 	value  interface{}
 
@@ -243,6 +242,36 @@ func (s *Chain) Related(value interface{}, foreign_keys ...string) *Chain {
 	return s
 }
 
+func (s *Chain) Begin() *Chain {
+	if db, ok := s.db.(sql_db); ok {
+		tx, err := db.Begin()
+		s.db = interface{}(tx).(sql_common)
+		s.err(err)
+	} else {
+		s.err(errors.New("Can't start a transaction."))
+	}
+
+	return s
+}
+
+func (s *Chain) Commit() *Chain {
+	if db, ok := s.db.(sql_tx); ok {
+		s.err(db.Commit())
+	} else {
+		s.err(errors.New("Commit is not supported, no database transaction found."))
+	}
+	return s
+}
+
+func (s *Chain) Rollback() *Chain {
+	if db, ok := s.db.(sql_tx); ok {
+		s.err(db.Rollback())
+	} else {
+		s.err(errors.New("Rollback is not supported, no database transaction found."))
+	}
+	return s
+}
+
 func (s *Chain) validSql(str string) (result bool) {
 	result = regexp.MustCompile("^\\s*[\\w\\s,.*()]*\\s*$").MatchString(str)
 	if !result {

db.go

@@ -0,0 +1,20 @@
+package gorm
+
+import "database/sql"
+
+type sql_common interface {
+	Exec(query string, args ...interface{}) (sql.Result, error)
+	Prepare(query string) (*sql.Stmt, error)
+	Query(query string, args ...interface{}) (*sql.Rows, error)
+	QueryRow(query string, args ...interface{}) *sql.Row
+}
+
+type sql_db interface {
+	Begin() (*sql.Tx, error)
+	SetMaxIdleConns(n int)
+}
+
+type sql_tx interface {
+	Commit() error
+	Rollback() error
+}

do.go

@@ -14,7 +14,7 @@ import (
 
 type Do struct {
 	chain              *Chain
-	db                 *sql.DB
+	db                 sql_common
 	driver             string
 	guessedTableName   string
 	specifiedTableName string

gorm_test.go

@@ -1329,6 +1329,41 @@ func TestSqlNullValue(t *testing.T) {
 	}
 }
 
+func TestTransaction(t *testing.T) {
+	d := db.Begin()
+	u := User{Name: "transcation"}
+	if err := d.Save(&u).Error; err != nil {
+		t.Errorf("No error should raise, but got", err)
+	}
+
+	if err := d.First(&User{}, "name = ?", "transcation").Error; err != nil {
+		t.Errorf("Should find saved record, but got", err)
+	}
+
+	d.Rollback()
+
+	if err := d.First(&User{}, "name = ?", "transcation").Error; err == nil {
+		t.Errorf("Should not find record after rollback")
+	}
+
+	d2 := db.Begin()
+	u2 := User{Name: "transcation-2"}
+	if err := d2.Save(&u2).Error; err != nil {
+		t.Errorf("No error should raise, but got", err)
+	}
+	d2.Update("age", 90)
+
+	if err := d2.First(&User{}, "name = ?", "transcation-2").Error; err != nil {
+		t.Errorf("Should find saved record, but got", err)
+	}
+
+	d2.Commit()
+
+	if err := db.First(&User{}, "name = ?", "transcation-2").Error; err != nil {
+		t.Errorf("Should be able to find committed record")
+	}
+}
+
 func BenchmarkGorm(b *testing.B) {
 	for x := 0; x < b.N; x++ {
 		email := BigEmail{Email: "benchmark@example.org", UserAgent: "pc", RegisteredAt: time.Now()}

logger.go

@@ -15,7 +15,7 @@ type Logger interface {
 }
 
 func print(level string, v ...interface{}) {
-	if logger_disabled {
+	if logger_disabled && level != "debug" {
 		return
 	}
 

main.go

@@ -5,7 +5,7 @@ import "database/sql"
 var singularTableName bool
 
 type DB struct {
-	db     *sql.DB
+	db     sql_common
 	driver string
 }
 
@@ -16,7 +16,9 @@ func Open(driver, source string) (db DB, err error) {
 }
 
 func (s *DB) SetPool(n int) {
-	s.db.SetMaxIdleConns(n)
+	if db, ok := s.db.(sql_db); ok {
+		db.SetMaxIdleConns(n)
+	}
 }
 
 func (s *DB) SetLogger(l interface{}) {
@@ -122,3 +124,7 @@ func (s *DB) DropTable(value interface{}) *Chain {
 func (s *DB) AutoMigrate(value interface{}) *Chain {
 	return s.buildChain().AutoMigrate(value)
 }
+
+func (s *DB) Begin() *Chain {
+	return s.buildChain().Begin()
+}