orm add atomic set value

@@ -382,17 +382,38 @@ func (d *dbBase) UpdateBatch(q dbQuerier, qs *querySet, mi *modelInfo, cond *Con
 
 	join := tables.getJoinSql()
 
-	var query string
+	var query, T, cols string
 
 	Q := d.ins.TableQuote()
 
 	if d.ins.SupportUpdateJoin() {
-		cols := strings.Join(columns, fmt.Sprintf("%s = ?, T0.%s", Q, Q))
-		query = fmt.Sprintf("UPDATE %s%s%s T0 %sSET T0.%s%s%s = ? %s", Q, mi.table, Q, join, Q, cols, Q, where)
+		T = "T0."
+	}
+
+	for i, v := range columns {
+		col := fmt.Sprintf("%s%s%s%s", T, Q, v, Q)
+		if c, ok := values[i].(colValue); ok {
+			switch c.opt {
+			case Col_Add:
+				cols += col + " = " + col + " + ? "
+			case Col_Minus:
+				cols += col + " = " + col + " - ? "
+			case Col_Multiply:
+				cols += col + " = " + col + " * ? "
+			case Col_Except:
+				cols += col + " = " + col + " / ? "
+			}
+			values[i] = c.value
+		} else {
+			cols += col + " = ? "
+		}
+	}
+
+	if d.ins.SupportUpdateJoin() {
+		query = fmt.Sprintf("UPDATE %s%s%s T0 %sSET %s%s", Q, mi.table, Q, join, cols, where)
 	} else {
-		cols := strings.Join(columns, fmt.Sprintf("%s = ?, %s", Q, Q))
 		supQuery := fmt.Sprintf("SELECT T0.%s%s%s FROM %s%s%s T0 %s%s", Q, mi.fields.pk.column, Q, Q, mi.table, Q, join, where)
-		query = fmt.Sprintf("UPDATE %s%s%s SET %s%s%s = ? WHERE %s%s%s IN ( %s )", Q, mi.table, Q, Q, cols, Q, Q, mi.fields.pk.column, Q, supQuery)
+		query = fmt.Sprintf("UPDATE %s%s%s SET %sWHERE %s%s%s IN ( %s )", Q, mi.table, Q, cols, Q, mi.fields.pk.column, Q, supQuery)
 	}
 
 	d.ins.ReplaceMarks(&query)

@@ -77,6 +77,7 @@ type User struct {
 	Profile    *Profile  `orm:"null;rel(one);on_delete(set_null)"`
 	Posts      []*Post   `orm:"reverse(many)" json:"-"`
 	ShouldSkip string    `orm:"-"`
+	Nums       int
 }
 
 func (u *User) TableIndex() [][]string {

@@ -4,6 +4,36 @@ import (
 	"fmt"
 )
 
+type colValue struct {
+	value int64
+	opt   operator
+}
+
+type operator int
+
+const (
+	Col_Add operator = iota
+	Col_Minus
+	Col_Multiply
+	Col_Except
+)
+
+func ColValue(opt operator, value interface{}) interface{} {
+	switch opt {
+	case Col_Add, Col_Minus, Col_Multiply, Col_Except:
+	default:
+		panic(fmt.Errorf("orm.ColValue wrong operator"))
+	}
+	v, err := StrTo(ToStr(value)).Int64()
+	if err != nil {
+		panic(fmt.Errorf("orm.ColValue doesn't support non string/numeric type, %s", err))
+	}
+	var val colValue
+	val.value = v
+	val.opt = opt
+	return val
+}
+
 type querySet struct {
 	mi       *modelInfo
 	cond     *Condition

@@ -1230,6 +1230,35 @@ func TestUpdate(t *testing.T) {
 	})
 	throwFail(t, err)
 	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Filter("user_name", "slene").Update(Params{
+		"Nums": ColValue(Col_Add, 100),
+	})
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Filter("user_name", "slene").Update(Params{
+		"Nums": ColValue(Col_Minus, 50),
+	})
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Filter("user_name", "slene").Update(Params{
+		"Nums": ColValue(Col_Multiply, 3),
+	})
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	num, err = qs.Filter("user_name", "slene").Update(Params{
+		"Nums": ColValue(Col_Except, 5),
+	})
+	throwFail(t, err)
+	throwFail(t, AssertIs(num, 1))
+
+	user := User{UserName: "slene"}
+	err = dORM.Read(&user, "UserName")
+	throwFail(t, err)
+	throwFail(t, AssertIs(user.Nums, 30))
 }
 
 func TestDelete(t *testing.T) {