some fix

@@ -406,7 +406,7 @@ func (d *dbTables) getLimitSql(offset int64, limit int) (limits string) {
 	if limit < 0 {
 		// no limit
 		if offset > 0 {
-			limits = fmt.Sprintf("OFFSET %d", offset)
+			limits = fmt.Sprintf("LIMIT 18446744073709551615 OFFSET %d", offset)
 		}
 	} else if offset <= 0 {
 		limits = fmt.Sprintf("LIMIT %d", limit)
@@ -732,7 +732,7 @@ func (d *dbBase) DeleteBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Con
 
 	refs := make([]interface{}, colsNum)
 	for i, _ := range refs {
-		var ref string
+		var ref interface{}
 		refs[i] = &ref
 	}
 
@@ -842,7 +842,7 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 
 	refs := make([]interface{}, colsNum)
 	for i, _ := range refs {
-		var ref string
+		var ref interface{}
 		refs[i] = &ref
 	}
 
@@ -882,6 +882,7 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 							lastm := mmi
 							mmi := fi.relModelInfo
 							field := reflect.Indirect(last.Field(fi.fieldIndex))
+							if field.IsValid() {
 								d.setColsValues(mmi, &field, mmi.fields.dbcols, trefs[:len(mmi.fields.dbcols)])
 								for _, fi := range mmi.fields.fieldsReverse {
 									if fi.reverseFieldInfo.mi == lastm {
@@ -890,11 +891,12 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 										}
 									}
 								}
-							trefs = trefs[len(mmi.fields.dbcols):]
 								cacheV[names] = &field
 								cacheM[names] = mmi
 								last = field
 							}
+							trefs = trefs[len(mmi.fields.dbcols):]
+						}
 					}
 				}
 			}
@@ -961,10 +963,15 @@ func (d *dbBase) GetOperatorSql(mi *modelInfo, operator string, args []interface
 		sql = operatorsSQL[operator]
 		arg := params[0]
 		switch operator {
+		case "exact":
+			if arg == nil {
+				params[0] = "IS NULL"
+			}
 		case "iexact", "contains", "icontains", "startswith", "endswith", "istartswith", "iendswith":
 			param := strings.Replace(ToStr(arg), `%`, `\%`, -1)
 			switch operator {
-			case "iexact", "contains", "icontains":
+			case "iexact":
+			case "contains", "icontains":
 				param = fmt.Sprintf("%%%s%%", param)
 			case "startswith", "istartswith":
 				param = fmt.Sprintf("%s%%", param)
@@ -1143,31 +1150,50 @@ setValue:
 	switch {
 	case fieldType == TypeBooleanField:
 		if isNative {
+			if value == nil {
+				value = false
+			}
 			field.SetBool(value.(bool))
 		}
 	case fieldType == TypeCharField || fieldType == TypeTextField:
 		if isNative {
+			if value == nil {
+				value = ""
+			}
 			field.SetString(value.(string))
 		}
 	case fieldType == TypeDateField || fieldType == TypeDateTimeField:
 		if isNative {
+			if value == nil {
+				value = time.Time{}
+			}
 			field.Set(reflect.ValueOf(value))
 		}
 	case fieldType&IsIntegerField > 0:
 		if fieldType&IsPostiveIntegerField > 0 {
 			if isNative {
+				if value == nil {
+					value = uint64(0)
+				}
 				field.SetUint(value.(uint64))
 			}
 		} else {
 			if isNative {
+				if value == nil {
+					value = int64(0)
+				}
 				field.SetInt(value.(int64))
 			}
 		}
 	case fieldType == TypeFloatField || fieldType == TypeDecimalField:
 		if isNative {
+			if value == nil {
+				value = float64(0)
+			}
 			field.SetFloat(value.(float64))
 		}
 	case fieldType&IsRelField > 0:
+		if value != nil {
 			fieldType = fi.relModelInfo.fields.pk[0].fieldType
 			mf := reflect.New(fi.relModelInfo.addrField.Elem().Type())
 			md := mf.Interface().(Modeler)
@@ -1177,169 +1203,6 @@ setValue:
 			field = &f
 			goto setValue
 		}
-
-	if isNative == false {
-		fd := field.Addr().Interface().(Fielder)
-		err := fd.SetRaw(value)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return value, nil
-}
-
-func (d *dbBase) xsetValue(fi *fieldInfo, val interface{}, field *reflect.Value) (interface{}, error) {
-	if val == nil {
-		return nil, nil
-	}
-
-	var value interface{}
-
-	var str *StrTo
-	switch v := val.(type) {
-	case []byte:
-		s := StrTo(string(v))
-		str = &s
-	case string:
-		s := StrTo(v)
-		str = &s
-	}
-
-	fieldType := fi.fieldType
-	isNative := fi.isFielder == false
-
-setValue:
-	switch {
-	case fieldType == TypeBooleanField:
-		if str == nil {
-			switch v := val.(type) {
-			case int64:
-				b := v == 1
-				if isNative {
-					field.SetBool(b)
-				}
-				value = b
-			default:
-				s := StrTo(ToStr(v))
-				str = &s
-			}
-		}
-		if str != nil {
-			b, err := str.Bool()
-			if err != nil {
-				return nil, err
-			}
-			if isNative {
-				field.SetBool(b)
-			}
-			value = b
-		}
-	case fieldType == TypeCharField || fieldType == TypeTextField:
-		s := str.String()
-		if str == nil {
-			s = ToStr(val)
-		}
-		if isNative {
-			field.SetString(s)
-		}
-		value = s
-	case fieldType == TypeDateField || fieldType == TypeDateTimeField:
-		if str == nil {
-			switch v := val.(type) {
-			case time.Time:
-				if isNative {
-					field.Set(reflect.ValueOf(v))
-				}
-				value = v
-			default:
-				s := StrTo(ToStr(v))
-				str = &s
-			}
-		}
-		if str != nil {
-			format := format_DateTime
-			if fi.fieldType == TypeDateField {
-				format = format_Date
-			}
-
-			t, err := timeParse(str.String(), format)
-			if err != nil {
-				return nil, err
-			}
-			if isNative {
-				field.Set(reflect.ValueOf(t))
-			}
-			value = t
-		}
-	case fieldType&IsIntegerField > 0:
-		if str == nil {
-			s := StrTo(ToStr(val))
-			str = &s
-		}
-		if str != nil {
-			var err error
-			switch fieldType {
-			case TypeSmallIntegerField:
-				value, err = str.Int16()
-			case TypeIntegerField:
-				value, err = str.Int32()
-			case TypeBigIntegerField:
-				value, err = str.Int64()
-			case TypePositiveSmallIntegerField:
-				value, err = str.Uint16()
-			case TypePositiveIntegerField:
-				value, err = str.Uint32()
-			case TypePositiveBigIntegerField:
-				value, err = str.Uint64()
-			}
-			if err != nil {
-				return nil, err
-			}
-			if fieldType&IsPostiveIntegerField > 0 {
-				v, _ := str.Uint64()
-				if isNative {
-					field.SetUint(v)
-				}
-			} else {
-				v, _ := str.Int64()
-				if isNative {
-					field.SetInt(v)
-				}
-			}
-		}
-	case fieldType == TypeFloatField || fieldType == TypeDecimalField:
-		if str == nil {
-			switch v := val.(type) {
-			case float64:
-				if isNative {
-					field.SetFloat(v)
-				}
-				value = v
-			default:
-				s := StrTo(ToStr(v))
-				str = &s
-			}
-		}
-		if str != nil {
-			v, err := str.Float64()
-			if err != nil {
-				return nil, err
-			}
-			if isNative {
-				field.SetFloat(v)
-			}
-			value = v
-		}
-	case fieldType&IsRelField > 0:
-		fieldType = fi.relModelInfo.fields.pk[0].fieldType
-		mf := reflect.New(fi.relModelInfo.addrField.Elem().Type())
-		md := mf.Interface().(Modeler)
-		md.Init(md)
-		field.Set(mf)
-		f := mf.Elem().Field(fi.relModelInfo.fields.pk[0].fieldIndex)
-		field = &f
-		goto setValue
 	}
 
 	if isNative == false {
@@ -1420,7 +1283,7 @@ func (d *dbBase) ReadValues(q dbQuerier, qs *querySet, mi *modelInfo, cond *Cond
 
 	refs := make([]interface{}, len(cols))
 	for i, _ := range refs {
-		var ref string
+		var ref interface{}
 		refs[i] = &ref
 	}
 

@@ -113,15 +113,18 @@ end:
 }
 
 func RegisterDriver(name string, typ driverType) {
-	if _, ok := drivers[name]; ok == false {
+	if t, ok := drivers[name]; ok == false {
 		drivers[name] = typ
 	} else {
-		fmt.Println("name `%s` db driver already registered")
+		if t != typ {
+			fmt.Println("name `%s` db driver already registered and is other type")
 			os.Exit(2)
 		}
+	}
 }
 
 func init() {
-	// RegisterDriver("mysql", DR_MySQL)
-	RegisterDriver("mymysql", DR_MySQL)
+	RegisterDriver("mysql", DR_MySQL)
+	RegisterDriver("postgres", DR_Postgres)
+	RegisterDriver("sqlite3", DR_Sqlite)
 }

@@ -26,7 +26,7 @@ var (
 		"auto":         1,
 		"auto_now":     1,
 		"auto_now_add": 1,
-		"max_length":   2,
+		"size":         2,
 		"choices":      2,
 		"column":       2,
 		"default":      2,
@@ -37,6 +37,7 @@ var (
 		"digits":       2,
 		"decimals":     2,
 		"on_delete":    2,
+		"type":         2,
 	}
 )
 

@@ -93,10 +93,16 @@ func (e *BooleanField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *BooleanField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(BooleanField)
+
 // A string field
-// required values tag: max_length
-// The max_length is enforced at the database level and in models’s validation.
-// eg: `max_length:"120"`
+// required values tag: size
+// The size is enforced at the database level and in models’s validation.
+// eg: `orm:"size(120)"`
 type CharField string
 
 func (e CharField) Value() string {
@@ -129,6 +135,12 @@ func (e *CharField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *CharField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(CharField)
+
 // A date, represented in go by a time.Time instance.
 // only date values like 2006-01-02
 // Has a few extra, optional attr tag:
@@ -141,7 +153,7 @@ func (e *CharField) RawValue() interface{} {
 // Automatically set the field to now when the object is first created. Useful for creation of timestamps.
 // Note that the current date is always used; it’s not just a default value that you can override.
 //
-// eg: `attr:"auto_now"` or `attr:"auto_now_add"`
+// eg: `orm:"auto_now"` or `orm:"auto_now_add"`
 type DateField time.Time
 
 func (e DateField) Value() time.Time {
@@ -180,6 +192,12 @@ func (e *DateField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *DateField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(DateField)
+
 // A date, represented in go by a time.Time instance.
 // datetime values like 2006-01-02 15:04:05
 // Takes the same extra arguments as DateField.
@@ -221,6 +239,12 @@ func (e *DateTimeField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *DateTimeField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(DateTimeField)
+
 // A floating-point number represented in go by a float32 value.
 type FloatField float64
 
@@ -261,6 +285,12 @@ func (e *FloatField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *FloatField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(FloatField)
+
 // -32768 to 32767
 type SmallIntegerField int16
 
@@ -299,6 +329,12 @@ func (e *SmallIntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *SmallIntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(SmallIntegerField)
+
 // -2147483648 to 2147483647
 type IntegerField int32
 
@@ -337,6 +373,12 @@ func (e *IntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *IntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(IntegerField)
+
 // -9223372036854775808 to 9223372036854775807.
 type BigIntegerField int64
 
@@ -375,6 +417,12 @@ func (e *BigIntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *BigIntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(BigIntegerField)
+
 // 0 to 65535
 type PositiveSmallIntegerField uint16
 
@@ -413,6 +461,12 @@ func (e *PositiveSmallIntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *PositiveSmallIntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(PositiveSmallIntegerField)
+
 // 0 to 4294967295
 type PositiveIntegerField uint32
 
@@ -451,6 +505,12 @@ func (e *PositiveIntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *PositiveIntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(PositiveIntegerField)
+
 // 0 to 18446744073709551615
 type PositiveBigIntegerField uint64
 
@@ -489,6 +549,12 @@ func (e *PositiveBigIntegerField) RawValue() interface{} {
 	return e.Value()
 }
 
+func (e *PositiveBigIntegerField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(PositiveBigIntegerField)
+
 // A large text field.
 type TextField string
 
@@ -521,3 +587,9 @@ func (e *TextField) SetRaw(value interface{}) error {
 func (e *TextField) RawValue() interface{} {
 	return e.Value()
 }
+
+func (e *TextField) Clean() error {
+	return nil
+}
+
+var _ Fielder = new(TextField)

@@ -145,7 +145,7 @@ type fieldInfo struct {
 	unique              bool
 	initial             StrTo
 	choices             fieldChoices
-	maxLength           int
+	size                int
 	auto_now            bool
 	auto_now_add        bool
 	rel                 bool
@@ -188,7 +188,7 @@ func newFieldInfo(mi *modelInfo, field reflect.Value, sf reflect.StructField) (f
 
 	digits := tags["digits"]
 	decimals := tags["decimals"]
-	maxLength := tags["max_length"]
+	size := tags["size"]
 	onDelete := tags["on_delete"]
 
 checkType:
@@ -248,13 +248,13 @@ checkType:
 		if err != nil {
 			goto end
 		}
-		if fieldType == TypeTextField && maxLength != "" {
+		if fieldType == TypeTextField && size != "" {
 			fieldType = TypeCharField
 		}
 		if fieldType == TypeFloatField && (digits != "" || decimals != "") {
 			fieldType = TypeDecimalField
 		}
-		if fieldType == TypeDateTimeField && attrs["date"] {
+		if fieldType == TypeDateTimeField && tags["type"] == "date" {
 			fieldType = TypeDateField
 		}
 	}
@@ -354,15 +354,15 @@ checkType:
 	switch fieldType {
 	case TypeBooleanField:
 	case TypeCharField:
-		if maxLength != "" {
-			v, e := StrTo(maxLength).Int32()
+		if size != "" {
+			v, e := StrTo(size).Int32()
 			if e != nil {
-				err = fmt.Errorf("wrong maxLength value `%s`", maxLength)
+				err = fmt.Errorf("wrong size value `%s`", size)
 			} else {
-				fi.maxLength = int(v)
+				fi.size = int(v)
 			}
 		} else {
-			err = fmt.Errorf("maxLength must be specify")
+			err = fmt.Errorf("size must be specify")
 		}
 	case TypeTextField:
 		fi.index = false
@@ -417,7 +417,6 @@ checkType:
 	}
 
 	if fi.unique {
-		fi.null = false
 		fi.blank = false
 		fi.index = false
 	}
@@ -484,7 +483,6 @@ checkType:
 
 	fi.choices = choices
 	fi.initial = initial
-
 end:
 	if err != nil {
 		return nil, err

@@ -2,15 +2,43 @@ package orm
 
 import ()
 
+type fieldError struct {
+	name string
+	err  error
+}
+
+func (f *fieldError) Name() string {
+	return f.name
+}
+
+func (f *fieldError) Error() error {
+	return f.err
+}
+
+func NewFieldError(name string, err error) IFieldError {
+	return &fieldError{name, err}
+}
+
 // non cleaned field errors
-type FieldErrors map[string]error
+type fieldErrors struct {
+	errors    map[string]IFieldError
+	errorList []IFieldError
+}
+
+func (fe *fieldErrors) Get(name string) IFieldError {
+	return fe.errors[name]
+}
+
+func (fe *fieldErrors) Set(name string, value IFieldError) {
+	fe.errors[name] = value
+}
 
-func (fe FieldErrors) Get(name string) error {
-	return fe[name]
+func (fe *fieldErrors) List() []IFieldError {
+	return fe.errorList
 }
 
-func (fe FieldErrors) Set(name string, value error) {
-	fe[name] = value
+func NewFieldErrors() IFieldErrors {
+	return &fieldErrors{errors: make(map[string]IFieldError)}
 }
 
 type Manager struct {
@@ -43,11 +71,11 @@ func (m *Manager) IsInited() bool {
 	return m.inited
 }
 
-func (m *Manager) Clean() FieldErrors {
+func (m *Manager) Clean() IFieldErrors {
 	return nil
 }
 
-func (m *Manager) CleanFields(name string) FieldErrors {
+func (m *Manager) CleanFields(name string) IFieldErrors {
 	return nil
 }
 

@@ -75,11 +75,20 @@ func (o *object) Update() (int64, error) {
 	if err != nil {
 		return num, err
 	}
-	return 0, nil
+	return num, nil
 }
 
 func (o *object) Delete() (int64, error) {
-	return o.orm.alias.DbBaser.Delete(o.orm.db, o.mi, o.ind)
+	num, err := o.orm.alias.DbBaser.Delete(o.orm.db, o.mi, o.ind)
+	if err != nil {
+		return num, err
+	}
+	if num > 0 {
+		if o.mi.fields.auto != nil {
+			o.ind.Field(o.mi.fields.auto.fieldIndex).SetInt(0)
+		}
+	}
+	return num, nil
 }
 
 func newObject(orm *orm, mi *modelInfo, md Modeler) ObjectSeter {

@@ -16,40 +16,46 @@ type querySet struct {
 }
 
 func (o *querySet) Filter(expr string, args ...interface{}) QuerySeter {
+	o = o.clone()
 	if o.cond == nil {
 		o.cond = NewCondition()
 	}
 	o.cond.And(expr, args...)
-	return o.Clone()
+	return o
 }
 
 func (o *querySet) Exclude(expr string, args ...interface{}) QuerySeter {
+	o = o.clone()
 	if o.cond == nil {
 		o.cond = NewCondition()
 	}
 	o.cond.AndNot(expr, args...)
-	return o.Clone()
+	return o
 }
 
 func (o *querySet) Limit(limit int, args ...int64) QuerySeter {
+	o = o.clone()
 	o.limit = limit
 	if len(args) > 0 {
 		o.offset = args[0]
 	}
-	return o.Clone()
+	return o
 }
 
 func (o *querySet) Offset(offset int64) QuerySeter {
+	o = o.clone()
 	o.offset = offset
-	return o.Clone()
+	return o
 }
 
-func (o *querySet) OrderBy(orders ...string) QuerySeter {
-	o.orders = orders
-	return o.Clone()
+func (o *querySet) OrderBy(exprs ...string) QuerySeter {
+	o = o.clone()
+	o.orders = exprs
+	return o
 }
 
 func (o *querySet) RelatedSel(params ...interface{}) QuerySeter {
+	o = o.clone()
 	var related []string
 	if len(params) == 0 {
 		o.relDepth = DefaultRelsDepth
@@ -66,19 +72,19 @@ func (o *querySet) RelatedSel(params ...interface{}) QuerySeter {
 		}
 	}
 	o.related = related
-	return o.Clone()
+	return o
 }
 
-func (o querySet) Clone() QuerySeter {
+func (o querySet) clone() *querySet {
 	if o.cond != nil {
 		o.cond = o.cond.Clone()
 	}
 	return &o
 }
 
-func (o *querySet) SetCond(cond *Condition) error {
+func (o querySet) SetCond(cond *Condition) QuerySeter {
 	o.cond = cond
-	return nil
+	return &o
 }
 
 func (o *querySet) Count() (int64, error) {
@@ -112,16 +118,16 @@ func (o *querySet) One(container Modeler) error {
 	return nil
 }
 
-func (o *querySet) Values(results *[]Params, args ...string) (int64, error) {
-	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, args, results)
+func (o *querySet) Values(results *[]Params, exprs ...string) (int64, error) {
+	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, exprs, results)
 }
 
-func (o *querySet) ValuesList(results *[]ParamsList, args ...string) (int64, error) {
-	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, args, results)
+func (o *querySet) ValuesList(results *[]ParamsList, exprs ...string) (int64, error) {
+	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, exprs, results)
 }
 
-func (o *querySet) ValuesFlat(result *ParamsList, arg string) (int64, error) {
-	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, []string{arg}, result)
+func (o *querySet) ValuesFlat(result *ParamsList, expr string) (int64, error) {
+	return o.orm.alias.DbBaser.ReadValues(o.orm.db, o, o.mi, o.cond, []string{expr}, result)
 }
 
 func newQuerySet(orm *orm, mi *modelInfo) QuerySeter {

@@ -10,13 +10,14 @@ type Fielder interface {
 	FieldType() int
 	SetRaw(interface{}) error
 	RawValue() interface{}
+	Clean() error
 }
 
 type Modeler interface {
 	Init(Modeler) Modeler
 	IsInited() bool
-	Clean() FieldErrors
-	CleanFields(string) FieldErrors
+	Clean() IFieldErrors
+	CleanFields(string) IFieldErrors
 	GetTableName() string
 }
 
@@ -48,8 +49,7 @@ type QuerySeter interface {
 	Offset(int64) QuerySeter
 	OrderBy(...string) QuerySeter
 	RelatedSel(...interface{}) QuerySeter
-	Clone() QuerySeter
-	SetCond(*Condition) error
+	SetCond(*Condition) QuerySeter
 	Count() (int64, error)
 	Update(Params) (int64, error)
 	Delete() (int64, error)
@@ -75,6 +75,17 @@ type RawSeter interface {
 	Prepare() (RawPreparer, error)
 }
 
+type IFieldError interface {
+	Name() string
+	Error() error
+}
+
+type IFieldErrors interface {
+	Get(string) IFieldError
+	Set(string, IFieldError)
+	List() []IFieldError
+}
+
 type dbQuerier interface {
 	Prepare(query string) (*sql.Stmt, error)
 	Exec(query string, args ...interface{}) (sql.Result, error)