diff --git a/orm/cmd_utils.go b/orm/cmd_utils.go
index 8117eaab..6fcb4b01 100644
--- a/orm/cmd_utils.go
+++ b/orm/cmd_utils.go
@@ -151,7 +151,11 @@ func getDbCreateSql(al *alias) (sqls []string, tableIndexes map[string][]dbIndex
 		}
 
 		if mi.model != nil {
-			for _, names := range getTableUnique(mi.addrField) {
+			allnames := getTableUnique(mi.addrField)
+			if !mi.manual && len(mi.uniques) > 0 {
+				allnames = append(allnames, mi.uniques)
+			}
+			for _, names := range allnames {
 				cols := make([]string, 0, len(names))
 				for _, name := range names {
 					if fi, ok := mi.fields.GetByAny(name); ok && fi.dbcol {
diff --git a/orm/db.go b/orm/db.go
index 5d2ad50e..8e25bf15 100644
--- a/orm/db.go
+++ b/orm/db.go
@@ -52,7 +52,6 @@ type dbBase struct {
 var _ dbBaser = new(dbBase)
 
 func (d *dbBase) collectValues(mi *modelInfo, ind reflect.Value, cols []string, skipAuto bool, insert bool, tz *time.Location) (columns []string, values []interface{}, err error) {
-	_, pkValue, _ := getExistPk(mi, ind)
 	for _, column := range cols {
 		var fi *fieldInfo
 		if fi, _ = mi.fields.GetByAny(column); fi != nil {
@@ -63,77 +62,9 @@ func (d *dbBase) collectValues(mi *modelInfo, ind reflect.Value, cols []string,
 		if fi.dbcol == false || fi.auto && skipAuto {
 			continue
 		}
-		var value interface{}
-		if fi.pk {
-			value = pkValue
-		} else {
-			field := ind.Field(fi.fieldIndex)
-			if fi.isFielder {
-				f := field.Addr().Interface().(Fielder)
-				value = f.RawValue()
-			} else {
-				switch fi.fieldType {
-				case TypeBooleanField:
-					value = field.Bool()
-				case TypeCharField, TypeTextField:
-					value = field.String()
-				case TypeFloatField, TypeDecimalField:
-					vu := field.Interface()
-					if _, ok := vu.(float32); ok {
-						value, _ = StrTo(ToStr(vu)).Float64()
-					} else {
-						value = field.Float()
-					}
-				case TypeDateField, TypeDateTimeField:
-					value = field.Interface()
-					if t, ok := value.(time.Time); ok {
-						if fi.fieldType == TypeDateField {
-							d.ins.TimeToDB(&t, DefaultTimeLoc)
-						} else {
-							d.ins.TimeToDB(&t, tz)
-						}
-						value = t
-					}
-				default:
-					switch {
-					case fi.fieldType&IsPostiveIntegerField > 0:
-						value = field.Uint()
-					case fi.fieldType&IsIntegerField > 0:
-						value = field.Int()
-					case fi.fieldType&IsRelField > 0:
-						if field.IsNil() {
-							value = nil
-						} else {
-							if _, vu, ok := getExistPk(fi.relModelInfo, reflect.Indirect(field)); ok {
-								value = vu
-							} else {
-								value = nil
-							}
-						}
-						if fi.null == false && value == nil {
-							return nil, nil, errors.New(fmt.Sprintf("field `%s` cannot be NULL", fi.fullName))
-						}
-					}
-				}
-			}
-			switch fi.fieldType {
-			case TypeDateField, TypeDateTimeField:
-				if fi.auto_now || fi.auto_now_add && insert {
-					tnow := time.Now()
-					if fi.fieldType == TypeDateField {
-						d.ins.TimeToDB(&tnow, DefaultTimeLoc)
-					} else {
-						d.ins.TimeToDB(&tnow, tz)
-					}
-					value = tnow
-					if fi.isFielder {
-						f := field.Addr().Interface().(Fielder)
-						f.SetRaw(tnow.In(DefaultTimeLoc))
-					} else {
-						field.Set(reflect.ValueOf(tnow.In(DefaultTimeLoc)))
-					}
-				}
-			}
+		value, err := d.collectFieldValue(mi, fi, ind, insert, tz)
+		if err != nil {
+			return nil, nil, err
 		}
 		columns = append(columns, column)
 		values = append(values, value)
@@ -141,6 +72,82 @@ func (d *dbBase) collectValues(mi *modelInfo, ind reflect.Value, cols []string,
 	return
 }
 
+func (d *dbBase) collectFieldValue(mi *modelInfo, fi *fieldInfo, ind reflect.Value, insert bool, tz *time.Location) (interface{}, error) {
+	var value interface{}
+	if fi.pk {
+		_, value, _ = getExistPk(mi, ind)
+	} else {
+		field := ind.Field(fi.fieldIndex)
+		if fi.isFielder {
+			f := field.Addr().Interface().(Fielder)
+			value = f.RawValue()
+		} else {
+			switch fi.fieldType {
+			case TypeBooleanField:
+				value = field.Bool()
+			case TypeCharField, TypeTextField:
+				value = field.String()
+			case TypeFloatField, TypeDecimalField:
+				vu := field.Interface()
+				if _, ok := vu.(float32); ok {
+					value, _ = StrTo(ToStr(vu)).Float64()
+				} else {
+					value = field.Float()
+				}
+			case TypeDateField, TypeDateTimeField:
+				value = field.Interface()
+				if t, ok := value.(time.Time); ok {
+					if fi.fieldType == TypeDateField {
+						d.ins.TimeToDB(&t, DefaultTimeLoc)
+					} else {
+						d.ins.TimeToDB(&t, tz)
+					}
+					value = t
+				}
+			default:
+				switch {
+				case fi.fieldType&IsPostiveIntegerField > 0:
+					value = field.Uint()
+				case fi.fieldType&IsIntegerField > 0:
+					value = field.Int()
+				case fi.fieldType&IsRelField > 0:
+					if field.IsNil() {
+						value = nil
+					} else {
+						if _, vu, ok := getExistPk(fi.relModelInfo, reflect.Indirect(field)); ok {
+							value = vu
+						} else {
+							value = nil
+						}
+					}
+					if fi.null == false && value == nil {
+						return nil, errors.New(fmt.Sprintf("field `%s` cannot be NULL", fi.fullName))
+					}
+				}
+			}
+		}
+		switch fi.fieldType {
+		case TypeDateField, TypeDateTimeField:
+			if fi.auto_now || fi.auto_now_add && insert {
+				tnow := time.Now()
+				if fi.fieldType == TypeDateField {
+					d.ins.TimeToDB(&tnow, DefaultTimeLoc)
+				} else {
+					d.ins.TimeToDB(&tnow, tz)
+				}
+				value = tnow
+				if fi.isFielder {
+					f := field.Addr().Interface().(Fielder)
+					f.SetRaw(tnow.In(DefaultTimeLoc))
+				} else {
+					field.Set(reflect.ValueOf(tnow.In(DefaultTimeLoc)))
+				}
+			}
+		}
+	}
+	return value, nil
+}
+
 func (d *dbBase) PrepareInsert(q dbQuerier, mi *modelInfo) (stmtQuerier, string, error) {
 	Q := d.ins.TableQuote()
 
@@ -250,6 +257,10 @@ func (d *dbBase) Insert(q dbQuerier, mi *modelInfo, ind reflect.Value, tz *time.
 		return 0, err
 	}
 
+	return d.InsertValue(q, mi, names, values)
+}
+
+func (d *dbBase) InsertValue(q dbQuerier, mi *modelInfo, names []string, values []interface{}) (int64, error) {
 	Q := d.ins.TableQuote()
 
 	marks := make([]string, len(names))
@@ -653,10 +664,12 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 			trefs = refs[len(tCols):]
 
 			for _, tbl := range tables.tables {
+				// loop selected tables
 				if tbl.sel {
 					last := mind
 					names := ""
 					mmi := mi
+					// loop cascade models
 					for _, name := range tbl.names {
 						names += name
 						if val, ok := cacheV[names]; ok {
@@ -665,27 +678,30 @@ func (d *dbBase) ReadBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Condi
 						} else {
 							fi := mmi.fields.GetByName(name)
 							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)], tz)
-								for _, fi := range mmi.fields.fieldsReverse {
-									if fi.inModel && fi.reverseFieldInfo.mi == lastm {
-										if fi.reverseFieldInfo != nil {
-											f := field.Field(fi.fieldIndex)
-											if f.Kind() == reflect.Ptr {
-												f.Set(last.Addr())
+							mmi = fi.relModelInfo
+							field := last
+							if last.Kind() != reflect.Invalid {
+								field = reflect.Indirect(last.Field(fi.fieldIndex))
+								if field.IsValid() {
+									d.setColsValues(mmi, &field, mmi.fields.dbcols, trefs[:len(mmi.fields.dbcols)], tz)
+									for _, fi := range mmi.fields.fieldsReverse {
+										if fi.inModel && fi.reverseFieldInfo.mi == lastm {
+											if fi.reverseFieldInfo != nil {
+												f := field.Field(fi.fieldIndex)
+												if f.Kind() == reflect.Ptr {
+													f.Set(last.Addr())
+												}
 											}
 										}
 									}
+									last = field
 								}
-								cacheV[names] = &field
-								cacheM[names] = mmi
-								last = field
 							}
-							trefs = trefs[len(mmi.fields.dbcols):]
+							cacheV[names] = &field
+							cacheM[names] = mmi
 						}
 					}
+					trefs = trefs[len(mmi.fields.dbcols):]
 				}
 			}
 
diff --git a/orm/db_tables.go b/orm/db_tables.go
index a49418c4..1ab47cdb 100644
--- a/orm/db_tables.go
+++ b/orm/db_tables.go
@@ -100,22 +100,29 @@ func (t *dbTables) parseRelated(rels []string, depth int) {
 			exs    = strings.Split(s, ExprSep)
 			names  = make([]string, 0, len(exs))
 			mmi    = t.mi
-			cansel = true
+			cancel = true
 			jtl    *dbTable
 		)
+
+		inner := true
+
 		for _, ex := range exs {
 			if fi, ok := mmi.fields.GetByAny(ex); ok && fi.rel && fi.fieldType != RelManyToMany {
 				names = append(names, fi.name)
 				mmi = fi.relModelInfo
 
-				jt := t.set(names, mmi, fi, fi.null == false)
+				if fi.null {
+					inner = false
+				}
+
+				jt := t.set(names, mmi, fi, inner)
 				jt.jtl = jtl
 
 				if fi.reverse {
-					cansel = false
+					cancel = false
 				}
 
-				if cansel {
+				if cancel {
 					jt.sel = depth > 0
 
 					if i < relsNum {
@@ -178,9 +185,8 @@ func (t *dbTables) getJoinSql() (join string) {
 	return
 }
 
-func (d *dbTables) parseExprs(mi *modelInfo, exprs []string) (index, name string, info *fieldInfo, success bool) {
+func (t *dbTables) parseExprs(mi *modelInfo, exprs []string) (index, name string, info *fieldInfo, success bool) {
 	var (
-		ffi *fieldInfo
 		jtl *dbTable
 		mmi = mi
 	)
@@ -188,73 +194,67 @@ func (d *dbTables) parseExprs(mi *modelInfo, exprs []string) (index, name string
 	num := len(exprs) - 1
 	names := make([]string, 0)
 
-	for i, ex := range exprs {
-		exist := false
+	inner := true
+
+	for i, ex := range exprs {
 
-	check:
 		fi, ok := mmi.fields.GetByAny(ex)
 
 		if ok {
 
-			if num != i {
-				names = append(names, fi.name)
+			isRel := fi.rel || fi.reverse
 
-				switch {
-				case fi.rel:
-					mmi = fi.relModelInfo
-					if fi.fieldType == RelManyToMany {
-						mmi = fi.relThroughModelInfo
-					}
-				case fi.reverse:
-					mmi = fi.reverseFieldInfo.mi
-					if fi.reverseFieldInfo.fieldType == RelManyToMany {
-						mmi = fi.reverseFieldInfo.relThroughModelInfo
-					}
-				default:
-					return
+			names = append(names, fi.name)
+
+			switch {
+			case fi.rel:
+				mmi = fi.relModelInfo
+				if fi.fieldType == RelManyToMany {
+					mmi = fi.relThroughModelInfo
+				}
+			case fi.reverse:
+				mmi = fi.reverseFieldInfo.mi
+			}
+
+			if isRel && (fi.mi.isThrough == false || num != i) {
+				if fi.null {
+					inner = false
 				}
 
-				jt, _ := d.add(names, mmi, fi, fi.null == false)
+				jt, _ := t.add(names, mmi, fi, inner)
 				jt.jtl = jtl
 				jtl = jt
+			}
 
-				if fi.rel && fi.fieldType == RelManyToMany {
-					ex = fi.relModelInfo.name
-					goto check
-				}
-
-				if fi.reverse && fi.reverseFieldInfo.fieldType == RelManyToMany {
-					ex = fi.reverseFieldInfo.mi.name
-					goto check
-				}
-
-				exist = true
-
-			} else {
-
-				if ffi == nil {
+			if num == i {
+				if i == 0 || jtl == nil {
 					index = "T0"
 				} else {
 					index = jtl.index
 				}
+
 				info = fi
-				if jtl != nil {
-					name = jtl.name + ExprSep + fi.name
-				} else {
+
+				if jtl == nil {
 					name = fi.name
+				} else {
+					name = jtl.name + ExprSep + fi.name
 				}
 
-				switch fi.fieldType {
-				case RelManyToMany, RelReverseMany:
-				default:
-					exist = true
+				switch {
+				case fi.rel:
+
+				case fi.reverse:
+					switch fi.reverseFieldInfo.fieldType {
+					case RelOneToOne, RelForeignKey:
+						index = jtl.index
+						info = fi.reverseFieldInfo.mi.fields.pk
+						name = info.name
+					}
 				}
 			}
 
-			ffi = fi
-		}
-
-		if exist == false {
+		} else {
 			index = ""
 			name = ""
 			info = nil
@@ -267,16 +267,15 @@ func (d *dbTables) parseExprs(mi *modelInfo, exprs []string) (index, name string
 	return
 }
 
-func (d *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (where string, params []interface{}) {
+func (t *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (where string, params []interface{}) {
 	if cond == nil || cond.IsEmpty() {
 		return
 	}
 
-	Q := d.base.TableQuote()
+	Q := t.base.TableQuote()
 
-	mi := d.mi
+	mi := t.mi
 
-	// outFor:
 	for i, p := range cond.params {
 		if i > 0 {
 			if p.isOr {
@@ -289,7 +288,7 @@ func (d *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (whe
 			where += "NOT "
 		}
 		if p.isCond {
-			w, ps := d.getCondSql(p.cond, true, tz)
+			w, ps := t.getCondSql(p.cond, true, tz)
 			if w != "" {
 				w = fmt.Sprintf("( %s) ", w)
 			}
@@ -305,7 +304,7 @@ func (d *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (whe
 				exprs = exprs[:num]
 			}
 
-			index, _, fi, suc := d.parseExprs(mi, exprs)
+			index, _, fi, suc := t.parseExprs(mi, exprs)
 			if suc == false {
 				panic(fmt.Errorf("unknown field/column name `%s`", strings.Join(p.exprs, ExprSep)))
 			}
@@ -314,10 +313,10 @@ func (d *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (whe
 				operator = "exact"
 			}
 
-			operSql, args := d.base.GenerateOperatorSql(mi, fi, operator, p.args, tz)
+			operSql, args := t.base.GenerateOperatorSql(mi, fi, operator, p.args, tz)
 
 			leftCol := fmt.Sprintf("%s.%s%s%s", index, Q, fi.column, Q)
-			d.base.GenerateOperatorLeftCol(fi, operator, &leftCol)
+			t.base.GenerateOperatorLeftCol(fi, operator, &leftCol)
 
 			where += fmt.Sprintf("%s %s ", leftCol, operSql)
 			params = append(params, args...)
@@ -332,12 +331,12 @@ func (d *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (whe
 	return
 }
 
-func (d *dbTables) getOrderSql(orders []string) (orderSql string) {
+func (t *dbTables) getOrderSql(orders []string) (orderSql string) {
 	if len(orders) == 0 {
 		return
 	}
 
-	Q := d.base.TableQuote()
+	Q := t.base.TableQuote()
 
 	orderSqls := make([]string, 0, len(orders))
 	for _, order := range orders {
@@ -348,7 +347,7 @@ func (d *dbTables) getOrderSql(orders []string) (orderSql string) {
 		}
 		exprs := strings.Split(order, ExprSep)
 
-		index, _, fi, suc := d.parseExprs(d.mi, exprs)
+		index, _, fi, suc := t.parseExprs(t.mi, exprs)
 		if suc == false {
 			panic(fmt.Errorf("unknown field/column name `%s`", strings.Join(exprs, ExprSep)))
 		}
@@ -360,14 +359,14 @@ func (d *dbTables) getOrderSql(orders []string) (orderSql string) {
 	return
 }
 
-func (d *dbTables) getLimitSql(mi *modelInfo, offset int64, limit int64) (limits string) {
+func (t *dbTables) getLimitSql(mi *modelInfo, offset int64, limit int64) (limits string) {
 	if limit == 0 {
 		limit = int64(DefaultRowsLimit)
 	}
 	if limit < 0 {
 		// no limit
 		if offset > 0 {
-			maxLimit := d.base.MaxLimit()
+			maxLimit := t.base.MaxLimit()
 			if maxLimit == 0 {
 				limits = fmt.Sprintf("OFFSET %d", offset)
 			} else {
diff --git a/orm/models_boot.go b/orm/models_boot.go
index 564d9b40..a8d3dbb8 100644
--- a/orm/models_boot.go
+++ b/orm/models_boot.go
@@ -121,7 +121,6 @@ func bootStrap() {
 							err = errors.New(msg)
 							goto end
 						}
-						err = nil
 					} else {
 						i := newM2MModelInfo(mi, mii)
 						if fi.relTable != "" {
@@ -135,6 +134,8 @@ func bootStrap() {
 						fi.relTable = i.table
 						fi.relThroughModelInfo = i
 					}
+
+					fi.relThroughModelInfo.isThrough = true
 				}
 			}
 		}
@@ -152,6 +153,7 @@ func bootStrap() {
 						break
 					}
 				}
+
 				if inModel == false {
 					rmi := fi.relModelInfo
 					ffi := new(fieldInfo)
@@ -185,9 +187,34 @@ func bootStrap() {
 		}
 	}
 
+	models = modelCache.all()
 	for _, mi := range models {
-		if fields, ok := mi.fields.fieldsByType[RelReverseOne]; ok {
-			for _, fi := range fields {
+		for _, fi := range mi.fields.fieldsRel {
+			switch fi.fieldType {
+			case RelManyToMany:
+				for _, ffi := range fi.relThroughModelInfo.fields.fieldsRel {
+					switch ffi.fieldType {
+					case RelOneToOne, RelForeignKey:
+						if ffi.relModelInfo == fi.relModelInfo {
+							fi.reverseFieldInfoTwo = ffi
+						}
+						if ffi.relModelInfo == mi {
+							fi.reverseField = ffi.name
+							fi.reverseFieldInfo = ffi
+						}
+					}
+				}
+
+				if fi.reverseFieldInfoTwo == nil {
+					err = fmt.Errorf("can not find m2m field for m2m model `%s`, ensure your m2m model defined correct",
+						fi.relThroughModelInfo.fullName)
+					goto end
+				}
+			}
+		}
+		for _, fi := range mi.fields.fieldsReverse {
+			switch fi.fieldType {
+			case RelReverseOne:
 				found := false
 			mForA:
 				for _, ffi := range fi.relModelInfo.fields.fieldsByType[RelOneToOne] {
@@ -195,6 +222,9 @@ func bootStrap() {
 						found = true
 						fi.reverseField = ffi.name
 						fi.reverseFieldInfo = ffi
+
+						ffi.reverseField = fi.name
+						ffi.reverseFieldInfo = fi
 						break mForA
 					}
 				}
@@ -202,10 +232,7 @@ func bootStrap() {
 					err = fmt.Errorf("reverse field `%s` not found in model `%s`", fi.fullName, fi.relModelInfo.fullName)
 					goto end
 				}
-			}
-		}
-		if fields, ok := mi.fields.fieldsByType[RelReverseMany]; ok {
-			for _, fi := range fields {
+			case RelReverseMany:
 				found := false
 			mForB:
 				for _, ffi := range fi.relModelInfo.fields.fieldsByType[RelForeignKey] {
@@ -213,6 +240,10 @@ func bootStrap() {
 						found = true
 						fi.reverseField = ffi.name
 						fi.reverseFieldInfo = ffi
+
+						ffi.reverseField = fi.name
+						ffi.reverseFieldInfo = fi
+
 						break mForB
 					}
 				}
@@ -221,14 +252,20 @@ func bootStrap() {
 					for _, ffi := range fi.relModelInfo.fields.fieldsByType[RelManyToMany] {
 						if ffi.relModelInfo == mi {
 							found = true
-							fi.reverseField = ffi.name
-							fi.reverseFieldInfo = ffi
+
+							fi.reverseField = ffi.reverseFieldInfoTwo.name
+							fi.reverseFieldInfo = ffi.reverseFieldInfoTwo
+							fi.relThroughModelInfo = ffi.relThroughModelInfo
+							fi.reverseFieldInfoTwo = ffi.reverseFieldInfo
+							fi.reverseFieldInfoM2M = ffi
+							ffi.reverseFieldInfoM2M = fi
+
 							break mForC
 						}
 					}
 				}
 				if found == false {
-					err = fmt.Errorf("reverse field `%s` not found in model `%s`", fi.fullName, fi.relModelInfo.fullName)
+					err = fmt.Errorf("reverse field for `%s` not found in model `%s`", fi.fullName, fi.relModelInfo.fullName)
 					goto end
 				}
 			}
diff --git a/orm/models_info_f.go b/orm/models_info_f.go
index 29ac3700..2252062a 100644
--- a/orm/models_info_f.go
+++ b/orm/models_info_f.go
@@ -103,6 +103,8 @@ type fieldInfo struct {
 	reverse             bool
 	reverseField        string
 	reverseFieldInfo    *fieldInfo
+	reverseFieldInfoTwo *fieldInfo
+	reverseFieldInfoM2M *fieldInfo
 	relTable            string
 	relThrough          string
 	relThroughModelInfo *modelInfo
diff --git a/orm/models_info_m.go b/orm/models_info_m.go
index 5b1e60ec..7a173781 100644
--- a/orm/models_info_m.go
+++ b/orm/models_info_m.go
@@ -16,6 +16,8 @@ type modelInfo struct {
 	fields    *fields
 	manual    bool
 	addrField reflect.Value
+	uniques   []string
+	isThrough bool
 }
 
 func newModelInfo(val reflect.Value) (info *modelInfo) {
@@ -118,5 +120,7 @@ func newM2MModelInfo(m1, m2 *modelInfo) (info *modelInfo) {
 	info.fields.Add(f1)
 	info.fields.Add(f2)
 	info.fields.pk = fa
+
+	info.uniques = []string{f1.column, f2.column}
 	return
 }
diff --git a/orm/models_test.go b/orm/models_test.go
index 1891393a..561d6254 100644
--- a/orm/models_test.go
+++ b/orm/models_test.go
@@ -99,10 +99,11 @@ func NewUser() *User {
 }
 
 type Profile struct {
-	Id    int
-	Age   int16
-	Money float64
-	User  *User `orm:"reverse(one)" json:"-"`
+	Id       int
+	Age      int16
+	Money    float64
+	User     *User `orm:"reverse(one)" json:"-"`
+	BestPost *Post `orm:"rel(one);null"`
 }
 
 func (u *Profile) TableName() string {
@@ -136,9 +137,10 @@ func NewPost() *Post {
 }
 
 type Tag struct {
-	Id    int
-	Name  string  `orm:"size(30)"`
-	Posts []*Post `orm:"reverse(many)" json:"-"`
+	Id       int
+	Name     string  `orm:"size(30)"`
+	BestPost *Post   `orm:"rel(one);null"`
+	Posts    []*Post `orm:"reverse(many)" json:"-"`
 }
 
 func NewTag() *Tag {
diff --git a/orm/orm.go b/orm/orm.go
index 35a94be2..4d343348 100644
--- a/orm/orm.go
+++ b/orm/orm.go
@@ -18,7 +18,7 @@ var (
 	Debug            = false
 	DebugLog         = NewLog(os.Stderr)
 	DefaultRowsLimit = 1000
-	DefaultRelsDepth = 5
+	DefaultRelsDepth = 2
 	DefaultTimeLoc   = time.Local
 	ErrTxHasBegan    = errors.New("<Ormer.Begin> transaction already begin")
 	ErrTxDone        = errors.New("<Ormer.Commit/Rollback> transaction not begin")
@@ -53,6 +53,14 @@ func (o *orm) getMiInd(md interface{}) (mi *modelInfo, ind reflect.Value) {
 	panic(fmt.Errorf("<Ormer> table: `%s` not found, maybe not RegisterModel", name))
 }
 
+func (o *orm) getFieldInfo(mi *modelInfo, name string) *fieldInfo {
+	fi, ok := mi.fields.GetByAny(name)
+	if !ok {
+		panic(fmt.Errorf("<Ormer> cannot find field `%s` for model `%s`", name, mi.fullName))
+	}
+	return fi
+}
+
 func (o *orm) Read(md interface{}, cols ...string) error {
 	mi, ind := o.getMiInd(md)
 	err := o.alias.DbBaser.Read(o.db, mi, ind, o.alias.TZ, cols)
@@ -107,22 +115,152 @@ func (o *orm) Delete(md interface{}) (int64, error) {
 	return num, nil
 }
 
-func (o *orm) M2mAdd(md interface{}, name string, mds ...interface{}) (int64, error) {
-	// TODO
-	panic(ErrNotImplement)
-	return 0, nil
+func (o *orm) QueryM2M(md interface{}, name string) QueryM2Mer {
+	mi, ind := o.getMiInd(md)
+	fi := o.getFieldInfo(mi, name)
+
+	if fi.fieldType != RelManyToMany {
+		panic(fmt.Errorf("<Ormer.QueryM2M> name `%s` for model `%s` is not a m2m field", fi.name, mi.fullName))
+	}
+
+	return newQueryM2M(md, o, mi, fi, ind)
 }
 
-func (o *orm) M2mDel(md interface{}, name string, mds ...interface{}) (int64, error) {
-	// TODO
-	panic(ErrNotImplement)
-	return 0, nil
+func (o *orm) LoadRelated(md interface{}, name string, args ...interface{}) (int64, error) {
+	_, fi, ind, qseter := o.queryRelated(md, name)
+
+	qs := qseter.(*querySet)
+
+	var relDepth int
+	var limit, offset int64
+	var order string
+	for i, arg := range args {
+		switch i {
+		case 0:
+			if v, ok := arg.(bool); ok {
+				if v {
+					relDepth = DefaultRelsDepth
+				}
+			} else if v, ok := arg.(int); ok {
+				relDepth = v
+			}
+		case 1:
+			limit = ToInt64(arg)
+		case 2:
+			offset = ToInt64(arg)
+		case 3:
+			order, _ = arg.(string)
+		}
+	}
+
+	switch fi.fieldType {
+	case RelOneToOne, RelForeignKey, RelReverseOne:
+		limit = 1
+		offset = 0
+	}
+
+	qs.limit = limit
+	qs.offset = offset
+	qs.relDepth = relDepth
+
+	if len(order) > 0 {
+		qs.orders = []string{order}
+	}
+
+	find := ind.Field(fi.fieldIndex)
+
+	var nums int64
+	var err error
+	switch fi.fieldType {
+	case RelOneToOne, RelForeignKey, RelReverseOne:
+		val := reflect.New(find.Type().Elem())
+		container := val.Interface()
+		err = qs.One(container)
+		if err == nil {
+			find.Set(val)
+			nums = 1
+		}
+	default:
+		nums, err = qs.All(find.Addr().Interface())
+	}
+
+	return nums, err
 }
 
-func (o *orm) LoadRel(md interface{}, name string) (int64, error) {
-	// TODO
-	panic(ErrNotImplement)
-	return 0, nil
+func (o *orm) QueryRelated(md interface{}, name string) QuerySeter {
+	// is this api needed ?
+	_, _, _, qs := o.queryRelated(md, name)
+	return qs
+}
+
+func (o *orm) queryRelated(md interface{}, name string) (*modelInfo, *fieldInfo, reflect.Value, QuerySeter) {
+	mi, ind := o.getMiInd(md)
+	fi := o.getFieldInfo(mi, name)
+
+	_, _, exist := getExistPk(mi, ind)
+	if exist == false {
+		panic(ErrMissPK)
+	}
+
+	var qs *querySet
+
+	switch fi.fieldType {
+	case RelOneToOne, RelForeignKey, RelManyToMany:
+		if !fi.inModel {
+			break
+		}
+		qs = o.getRelQs(md, mi, fi)
+	case RelReverseOne, RelReverseMany:
+		if !fi.inModel {
+			break
+		}
+		qs = o.getReverseQs(md, mi, fi)
+	}
+
+	if qs == nil {
+		panic(fmt.Errorf("<Ormer> name `%s` for model `%s` is not an available rel/reverse field"))
+	}
+
+	return mi, fi, ind, qs
+}
+
+func (o *orm) getReverseQs(md interface{}, mi *modelInfo, fi *fieldInfo) *querySet {
+	switch fi.fieldType {
+	case RelReverseOne, RelReverseMany:
+	default:
+		panic(fmt.Errorf("<Ormer> name `%s` for model `%s` is not an available reverse field", fi.name, mi.fullName))
+	}
+
+	var q *querySet
+
+	if fi.fieldType == RelReverseMany && fi.reverseFieldInfo.mi.isThrough {
+		q = newQuerySet(o, fi.relModelInfo).(*querySet)
+		q.cond = NewCondition().And(fi.reverseFieldInfoM2M.column+ExprSep+fi.reverseFieldInfo.column, md)
+	} else {
+		q = newQuerySet(o, fi.reverseFieldInfo.mi).(*querySet)
+		q.cond = NewCondition().And(fi.reverseFieldInfo.column, md)
+	}
+
+	return q
+}
+
+func (o *orm) getRelQs(md interface{}, mi *modelInfo, fi *fieldInfo) *querySet {
+	switch fi.fieldType {
+	case RelOneToOne, RelForeignKey, RelManyToMany:
+	default:
+		panic(fmt.Errorf("<Ormer> name `%s` for model `%s` is not an available rel field", fi.name, mi.fullName))
+	}
+
+	q := newQuerySet(o, fi.relModelInfo).(*querySet)
+	q.cond = NewCondition()
+
+	if fi.fieldType == RelManyToMany {
+		q.cond = q.cond.And(fi.reverseFieldInfoM2M.column+ExprSep+fi.reverseFieldInfo.column, md)
+	} else {
+		q.cond = q.cond.And(fi.reverseFieldInfo.column, md)
+	}
+
+	return q
 }
 
 func (o *orm) QueryTable(ptrStructOrTableName interface{}) (qs QuerySeter) {
diff --git a/orm/orm_querym2m.go b/orm/orm_querym2m.go
new file mode 100644
index 00000000..876fc37e
--- /dev/null
+++ b/orm/orm_querym2m.go
@@ -0,0 +1,111 @@
+package orm
+
+import (
+	"reflect"
+)
+
+type queryM2M struct {
+	md  interface{}
+	mi  *modelInfo
+	fi  *fieldInfo
+	qs  *querySet
+	ind reflect.Value
+}
+
+func (o *queryM2M) Add(mds ...interface{}) (int64, error) {
+	fi := o.fi
+	mi := fi.relThroughModelInfo
+	mfi := fi.reverseFieldInfo
+	rfi := fi.reverseFieldInfoTwo
+
+	orm := o.qs.orm
+	dbase := orm.alias.DbBaser
+
+	var models []interface{}
+
+	for _, md := range mds {
+		val := reflect.ValueOf(md)
+		if val.Kind() == reflect.Slice || val.Kind() == reflect.Array {
+			for i := 0; i < val.Len(); i++ {
+				v := val.Index(i)
+				if v.CanInterface() {
+					models = append(models, v.Interface())
+				}
+			}
+		} else {
+			models = append(models, md)
+		}
+	}
+
+	_, v1, exist := getExistPk(o.mi, o.ind)
+	if exist == false {
+		panic(ErrMissPK)
+	}
+
+	names := []string{mfi.column, rfi.column}
+
+	var nums int64
+	for _, md := range models {
+
+		ind := reflect.Indirect(reflect.ValueOf(md))
+
+		var v2 interface{}
+		if ind.Kind() != reflect.Struct {
+			v2 = ind.Interface()
+		} else {
+			_, v2, exist = getExistPk(fi.relModelInfo, ind)
+			if exist == false {
+				panic(ErrMissPK)
+			}
+		}
+
+		values := []interface{}{v1, v2}
+		_, err := dbase.InsertValue(orm.db, mi, names, values)
+		if err != nil {
+			return nums, err
+		}
+
+		nums += 1
+	}
+
+	return nums, nil
+}
+
+func (o *queryM2M) Remove(mds ...interface{}) (int64, error) {
+	fi := o.fi
+	qs := o.qs.Filter(fi.reverseFieldInfo.name, o.md)
+
+	nums, err := qs.Filter(fi.reverseFieldInfoTwo.name+ExprSep+"in", mds).Delete()
+	if err != nil {
+		return nums, err
+	}
+	return nums, nil
+}
+
+func (o *queryM2M) Exist(md interface{}) bool {
+	fi := o.fi
+	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).
+		Filter(fi.reverseFieldInfoTwo.name, md).Exist()
+}
+
+func (o *queryM2M) Clear() (int64, error) {
+	fi := o.fi
+	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).Delete()
+}
+
+func (o *queryM2M) Count() (int64, error) {
+	fi := o.fi
+	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).Count()
+}
+
+var _ QueryM2Mer = new(queryM2M)
+
+func newQueryM2M(md interface{}, o *orm, mi *modelInfo, fi *fieldInfo, ind reflect.Value) QueryM2Mer {
+	qm2m := new(queryM2M)
+	qm2m.md = md
+	qm2m.mi = mi
+	qm2m.fi = fi
+	qm2m.ind = ind
+	qm2m.qs = newQuerySet(o, fi.relThroughModelInfo).(*querySet)
+	return qm2m
+}
diff --git a/orm/orm_test.go b/orm/orm_test.go
index 37baff9d..79fccf5b 100644
--- a/orm/orm_test.go
+++ b/orm/orm_test.go
@@ -48,9 +48,9 @@ func ValuesCompare(is bool, a interface{}, args ...interface{}) (err error, ok b
 	ok = is && ok || !is && !ok
 	if !ok {
 		if is {
-			err = fmt.Errorf("expected: a == `%v`, get `%v`", b, a)
+			err = fmt.Errorf("expected: `%v`, get `%v`", b, a)
 		} else {
-			err = fmt.Errorf("expected: a != `%v`, get `%v`", b, a)
+			err = fmt.Errorf("expected: `%v`, get `%v`", b, a)
 		}
 	}
 
@@ -419,7 +419,7 @@ func TestInsertTestData(t *testing.T) {
 	throwFail(t, AssertIs(id, 4))
 
 	tags := []*Tag{
-		&Tag{Name: "golang"},
+		&Tag{Name: "golang", BestPost: &Post{Id: 2}},
 		&Tag{Name: "example"},
 		&Tag{Name: "format"},
 		&Tag{Name: "c++"},
@@ -454,7 +454,13 @@ The program—and web server—godoc processes Go source files to extract docume
 		id, err := dORM.Insert(post)
 		throwFail(t, err)
 		throwFail(t, AssertIs(id > 0, true))
-		// dORM.M2mAdd(post, "tags", post.Tags)
+
+		num := len(post.Tags)
+		if num > 0 {
+			nums, err := dORM.QueryM2M(post, "tags").Add(post.Tags)
+			throwFailNow(t, err)
+			throwFailNow(t, AssertIs(nums, num))
+		}
 	}
 
 	for _, comment := range comments {
@@ -590,6 +596,68 @@ func TestOperators(t *testing.T) {
 	throwFail(t, AssertIs(num, 2))
 }
 
+func TestSetCond(t *testing.T) {
+	cond := NewCondition()
+	cond1 := cond.And("profile__isnull", false).AndNot("status__in", 1).Or("profile__age__gt", 2000)
+
+	qs := dORM.QueryTable("user")
+	num, err := qs.SetCond(cond1).Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	cond2 := cond.AndCond(cond1).OrCond(cond.And("user_name", "slene"))
+	num, err = qs.SetCond(cond2).Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 2))
+}
+
+func TestLimit(t *testing.T) {
+	var posts []*Post
+	qs := dORM.QueryTable("post")
+	num, err := qs.Limit(1).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Limit(-1).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 4))
+
+	num, err = qs.Limit(-1, 2).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 2))
+
+	num, err = qs.Limit(0, 2).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 2))
+}
+
+func TestOffset(t *testing.T) {
+	var posts []*Post
+	qs := dORM.QueryTable("post")
+	num, err := qs.Limit(1).Offset(2).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Offset(2).All(&posts)
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 2))
+}
+
+func TestOrderBy(t *testing.T) {
+	qs := dORM.QueryTable("user")
+	num, err := qs.OrderBy("-status").Filter("user_name", "nobody").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.OrderBy("status").Filter("user_name", "slene").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.OrderBy("-profile__age").Filter("user_name", "astaxie").Count()
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+}
+
 func TestAll(t *testing.T) {
 	var users []*User
 	qs := dORM.QueryTable("user")
@@ -758,66 +826,292 @@ func TestRelatedSel(t *testing.T) {
 	throwFailNow(t, AssertIs(posts[3].User.UserName, "nobody"))
 }
 
-func TestSetCond(t *testing.T) {
-	cond := NewCondition()
-	cond1 := cond.And("profile__isnull", false).AndNot("status__in", 1).Or("profile__age__gt", 2000)
+func TestReverseQuery(t *testing.T) {
+	var profile Profile
+	err := dORM.QueryTable("user_profile").Filter("User", 3).One(&profile)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(profile.Age, 30))
 
-	qs := dORM.QueryTable("user")
-	num, err := qs.SetCond(cond1).Count()
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+	profile = Profile{}
+	err = dORM.QueryTable("user_profile").Filter("User__UserName", "astaxie").One(&profile)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(profile.Age, 30))
 
-	cond2 := cond.AndCond(cond1).OrCond(cond.And("user_name", "slene"))
-	num, err = qs.SetCond(cond2).Count()
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 2))
-}
+	var user User
+	err = dORM.QueryTable("user").Filter("Posts__Title", "Examples").One(&user)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(user.UserName, "astaxie"))
+
+	user = User{}
+	err = dORM.QueryTable("user").Filter("Posts__User__UserName", "astaxie").Limit(1).One(&user)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(user.UserName, "astaxie"))
+
+	user = User{}
+	err = dORM.QueryTable("user").Filter("Posts__User__UserName", "astaxie").RelatedSel().Limit(1).One(&user)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(user.UserName, "astaxie"))
+	throwFailNow(t, AssertIs(user.Profile == nil, false))
+	throwFailNow(t, AssertIs(user.Profile.Age, 30))
 
-func TestLimit(t *testing.T) {
 	var posts []*Post
-	qs := dORM.QueryTable("post")
-	num, err := qs.Limit(1).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+	num, err := dORM.QueryTable("post").Filter("Tags__Tag__Name", "golang").All(&posts)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 3))
+	throwFailNow(t, AssertIs(posts[0].Title, "Introduction"))
 
-	num, err = qs.Limit(-1).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 4))
+	posts = []*Post{}
+	num, err = dORM.QueryTable("post").Filter("Tags__Tag__Name", "golang").Filter("User__UserName", "slene").All(&posts)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(posts[0].Title, "Introduction"))
 
-	num, err = qs.Limit(-1, 2).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 2))
+	posts = []*Post{}
+	num, err = dORM.QueryTable("post").Filter("Tags__Tag__Name", "golang").
+		Filter("User__UserName", "slene").RelatedSel().All(&posts)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(posts[0].User == nil, false))
+	throwFailNow(t, AssertIs(posts[0].User.UserName, "slene"))
 
-	num, err = qs.Limit(0, 2).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 2))
+	var tags []*Tag
+	num, err = dORM.QueryTable("tag").Filter("Posts__Post__Title", "Introduction").All(&tags)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(tags[0].Name, "golang"))
+
+	tags = []*Tag{}
+	num, err = dORM.QueryTable("tag").Filter("Posts__Post__Title", "Introduction").
+		Filter("BestPost__User__UserName", "astaxie").All(&tags)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(tags[0].Name, "golang"))
+
+	tags = []*Tag{}
+	num, err = dORM.QueryTable("tag").Filter("Posts__Post__Title", "Introduction").
+		Filter("BestPost__User__UserName", "astaxie").RelatedSel().All(&tags)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(tags[0].Name, "golang"))
+	throwFailNow(t, AssertIs(tags[0].BestPost == nil, false))
+	throwFailNow(t, AssertIs(tags[0].BestPost.Title, "Examples"))
+	throwFailNow(t, AssertIs(tags[0].BestPost.User == nil, false))
+	throwFailNow(t, AssertIs(tags[0].BestPost.User.UserName, "astaxie"))
 }
 
-func TestOffset(t *testing.T) {
-	var posts []*Post
-	qs := dORM.QueryTable("post")
-	num, err := qs.Limit(1).Offset(2).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+func TestLoadRelated(t *testing.T) {
+	// load reverse foreign key
+	user := User{Id: 3}
 
-	num, err = qs.Offset(2).All(&posts)
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 2))
+	err := dORM.Read(&user)
+	throwFailNow(t, err)
+
+	num, err := dORM.LoadRelated(&user, "Posts")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 2))
+	throwFailNow(t, AssertIs(len(user.Posts), 2))
+	throwFailNow(t, AssertIs(user.Posts[0].User.Id, 3))
+
+	num, err = dORM.LoadRelated(&user, "Posts", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(len(user.Posts), 2))
+	throwFailNow(t, AssertIs(user.Posts[0].User.UserName, "astaxie"))
+
+	num, err = dORM.LoadRelated(&user, "Posts", true, 1)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(len(user.Posts), 1))
+
+	num, err = dORM.LoadRelated(&user, "Posts", true, 0, 0, "-Id")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(len(user.Posts), 2))
+	throwFailNow(t, AssertIs(user.Posts[0].Title, "Formatting"))
+
+	num, err = dORM.LoadRelated(&user, "Posts", true, 1, 1, "Id")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(len(user.Posts), 1))
+	throwFailNow(t, AssertIs(user.Posts[0].Title, "Formatting"))
+
+	// load reverse one to one
+	profile := Profile{Id: 3}
+	profile.BestPost = &Post{Id: 2}
+	num, err = dORM.Update(&profile, "BestPost")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+
+	err = dORM.Read(&profile)
+	throwFailNow(t, err)
+
+	num, err = dORM.LoadRelated(&profile, "User")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(profile.User == nil, false))
+	throwFailNow(t, AssertIs(profile.User.UserName, "astaxie"))
+
+	num, err = dORM.LoadRelated(&profile, "User", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(profile.User == nil, false))
+	throwFailNow(t, AssertIs(profile.User.UserName, "astaxie"))
+	throwFailNow(t, AssertIs(profile.User.Profile.Age, profile.Age))
+
+	// load rel one to one
+	err = dORM.Read(&user)
+	throwFailNow(t, err)
+
+	num, err = dORM.LoadRelated(&user, "Profile")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(user.Profile == nil, false))
+	throwFailNow(t, AssertIs(user.Profile.Age, 30))
+
+	num, err = dORM.LoadRelated(&user, "Profile", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(user.Profile == nil, false))
+	throwFailNow(t, AssertIs(user.Profile.Age, 30))
+	throwFailNow(t, AssertIs(user.Profile.BestPost == nil, false))
+	throwFailNow(t, AssertIs(user.Profile.BestPost.Title, "Examples"))
+
+	post := Post{Id: 2}
+
+	// load rel foreign key
+	err = dORM.Read(&post)
+	throwFailNow(t, err)
+
+	num, err = dORM.LoadRelated(&post, "User")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(post.User == nil, false))
+	throwFailNow(t, AssertIs(post.User.UserName, "astaxie"))
+
+	num, err = dORM.LoadRelated(&post, "User", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+	throwFailNow(t, AssertIs(post.User == nil, false))
+	throwFailNow(t, AssertIs(post.User.UserName, "astaxie"))
+	throwFailNow(t, AssertIs(post.User.Profile == nil, false))
+	throwFailNow(t, AssertIs(post.User.Profile.Age, 30))
+
+	// load rel m2m
+	post = Post{Id: 2}
+
+	err = dORM.Read(&post)
+	throwFailNow(t, err)
+
+	num, err = dORM.LoadRelated(&post, "Tags")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 2))
+	throwFailNow(t, AssertIs(len(post.Tags), 2))
+	throwFailNow(t, AssertIs(post.Tags[0].Name, "golang"))
+
+	num, err = dORM.LoadRelated(&post, "Tags", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 2))
+	throwFailNow(t, AssertIs(len(post.Tags), 2))
+	throwFailNow(t, AssertIs(post.Tags[0].Name, "golang"))
+	throwFailNow(t, AssertIs(post.Tags[0].BestPost == nil, false))
+	throwFailNow(t, AssertIs(post.Tags[0].BestPost.User.UserName, "astaxie"))
+
+	// load reverse m2m
+	tag := Tag{Id: 1}
+
+	err = dORM.Read(&tag)
+	throwFailNow(t, err)
+
+	num, err = dORM.LoadRelated(&tag, "Posts")
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 3))
+	throwFailNow(t, AssertIs(tag.Posts[0].Title, "Introduction"))
+	throwFailNow(t, AssertIs(tag.Posts[0].User.Id, 2))
+	throwFailNow(t, AssertIs(tag.Posts[0].User.Profile == nil, true))
+
+	num, err = dORM.LoadRelated(&tag, "Posts", true)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 3))
+	throwFailNow(t, AssertIs(tag.Posts[0].Title, "Introduction"))
+	throwFailNow(t, AssertIs(tag.Posts[0].User.Id, 2))
+	throwFailNow(t, AssertIs(tag.Posts[0].User.UserName, "slene"))
 }
 
-func TestOrderBy(t *testing.T) {
-	qs := dORM.QueryTable("user")
-	num, err := qs.OrderBy("-status").Filter("user_name", "nobody").Count()
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+func TestQueryM2M(t *testing.T) {
+	post := Post{Id: 4}
+	m2m := dORM.QueryM2M(&post, "Tags")
 
-	num, err = qs.OrderBy("status").Filter("user_name", "slene").Count()
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+	tag1 := []*Tag{&Tag{Name: "TestTag1"}, &Tag{Name: "TestTag2"}}
+	tag2 := &Tag{Name: "TestTag3"}
+	tag3 := []interface{}{&Tag{Name: "TestTag4"}}
 
-	num, err = qs.OrderBy("-profile__age").Filter("user_name", "astaxie").Count()
-	throwFail(t, err)
-	throwFail(t, AssertIs(num, 1))
+	tags := []interface{}{tag1[0], tag1[1], tag2, tag3[0]}
+
+	for _, tag := range tags {
+		_, err := dORM.Insert(tag)
+		throwFailNow(t, err)
+	}
+
+	num, err := m2m.Add(tag1)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 2))
+
+	num, err = m2m.Add(tag2)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+
+	num, err = m2m.Add(tag3)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+
+	num, err = m2m.Count()
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 5))
+
+	num, err = m2m.Remove(tag3)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+
+	num, err = m2m.Count()
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 4))
+
+	exist := m2m.Exist(tag2)
+	throwFailNow(t, AssertIs(exist, true))
+
+	num, err = m2m.Remove(tag2)
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 1))
+
+	exist = m2m.Exist(tag2)
+	throwFailNow(t, AssertIs(exist, false))
+
+	num, err = m2m.Count()
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 3))
+
+	num, err = m2m.Clear()
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 3))
+
+	num, err = m2m.Count()
+	throwFailNow(t, err)
+	throwFailNow(t, AssertIs(num, 0))
+}
+
+func TestQueryRelate(t *testing.T) {
+	// post := &Post{Id: 2}
+
+	// qs := dORM.QueryRelate(post, "Tags")
+	// num, err := qs.Count()
+	// throwFailNow(t, err)
+	// throwFailNow(t, AssertIs(num, 2))
+
+	// var tags []*Tag
+	// num, err = qs.All(&tags)
+	// throwFailNow(t, err)
+	// throwFailNow(t, AssertIs(num, 2))
+	// throwFailNow(t, AssertIs(tags[0].Name, "golang"))
+
+	// num, err = dORM.QueryTable("Tag").Filter("Posts__Post", 2).Count()
+	// throwFailNow(t, err)
+	// throwFailNow(t, AssertIs(num, 2))
 }
 
 func TestPrepareInsert(t *testing.T) {
diff --git a/orm/types.go b/orm/types.go
index bf18e2c2..89af9d92 100644
--- a/orm/types.go
+++ b/orm/types.go
@@ -24,9 +24,8 @@ type Ormer interface {
 	Insert(interface{}) (int64, error)
 	Update(interface{}, ...string) (int64, error)
 	Delete(interface{}) (int64, error)
-	M2mAdd(interface{}, string, ...interface{}) (int64, error)
-	M2mDel(interface{}, string, ...interface{}) (int64, error)
-	LoadRel(interface{}, string) (int64, error)
+	LoadRelated(interface{}, string, ...interface{}) (int64, error)
+	QueryM2M(interface{}, string) QueryM2Mer
 	QueryTable(interface{}) QuerySeter
 	Using(string) error
 	Begin() error
@@ -61,6 +60,14 @@ type QuerySeter interface {
 	ValuesFlat(*ParamsList, string) (int64, error)
 }
 
+type QueryM2Mer interface {
+	Add(...interface{}) (int64, error)
+	Remove(...interface{}) (int64, error)
+	Exist(interface{}) bool
+	Clear() (int64, error)
+	Count() (int64, error)
+}
+
 type RawPreparer interface {
 	Exec(...interface{}) (sql.Result, error)
 	Close() error
@@ -114,6 +121,7 @@ type txEnder interface {
 type dbBaser interface {
 	Read(dbQuerier, *modelInfo, reflect.Value, *time.Location, []string) error
 	Insert(dbQuerier, *modelInfo, reflect.Value, *time.Location) (int64, error)
+	InsertValue(dbQuerier, *modelInfo, []string, []interface{}) (int64, error)
 	InsertStmt(stmtQuerier, *modelInfo, reflect.Value, *time.Location) (int64, error)
 	Update(dbQuerier, *modelInfo, reflect.Value, *time.Location, []string) (int64, error)
 	Delete(dbQuerier, *modelInfo, reflect.Value, *time.Location) (int64, error)
@@ -139,4 +147,5 @@ type dbBaser interface {
 	ShowTablesQuery() string
 	ShowColumnsQuery(string) string
 	IndexExists(dbQuerier, string, string) bool
+	collectFieldValue(*modelInfo, *fieldInfo, reflect.Value, bool, *time.Location) (interface{}, error)
 }