orm support use any numeric type set QuerySeter.Limit value

@@ -360,9 +360,9 @@ func (d *dbTables) getOrderSql(orders []string) (orderSql string) {
 	return
 }
 
-func (d *dbTables) getLimitSql(mi *modelInfo, offset int64, limit int) (limits string) {
+func (d *dbTables) getLimitSql(mi *modelInfo, offset int64, limit int64) (limits string) {
 	if limit == 0 {
-		limit = DefaultRowsLimit
+		limit = int64(DefaultRowsLimit)
 	}
 	if limit < 0 {
 		// no limit

@@ -2,7 +2,6 @@ package orm
 
 import (
 	"fmt"
-	"reflect"
 )
 
 type querySet struct {
@@ -10,7 +9,7 @@ type querySet struct {
 	cond     *Condition
 	related  []string
 	relDepth int
-	limit    int
+	limit    int64
 	offset   int64
 	orders   []string
 	orm      *orm
@@ -35,19 +34,11 @@ func (o querySet) Exclude(expr string, args ...interface{}) QuerySeter {
 }
 
 func (o *querySet) setOffset(num interface{}) {
-	val := reflect.ValueOf(num)
-	switch num.(type) {
-	case int, int8, int16, int32, int64:
-		o.offset = val.Int()
-	case uint, uint8, uint16, uint32, uint64:
-		o.offset = int64(val.Uint())
-	default:
-		panic(fmt.Errorf("<QuerySeter> offset value need numeric not `%T`", num))
-	}
+	o.offset = ToInt64(num)
 }
 
-func (o querySet) Limit(limit int, args ...interface{}) QuerySeter {
-	o.limit = limit
+func (o querySet) Limit(limit interface{}, args ...interface{}) QuerySeter {
+	o.limit = ToInt64(limit)
 	if len(args) > 0 {
 		o.setOffset(args[0])
 	}

@@ -45,7 +45,7 @@ type QuerySeter interface {
 	Filter(string, ...interface{}) QuerySeter
 	Exclude(string, ...interface{}) QuerySeter
 	SetCond(*Condition) QuerySeter
-	Limit(int, ...interface{}) QuerySeter
+	Limit(interface{}, ...interface{}) QuerySeter
 	Offset(interface{}) QuerySeter
 	OrderBy(...string) QuerySeter
 	RelatedSel(...interface{}) QuerySeter

@@ -2,6 +2,7 @@ package orm
 
 import (
 	"fmt"
+	"reflect"
 	"strconv"
 	"strings"
 	"time"
@@ -133,6 +134,19 @@ func ToStr(value interface{}, args ...int) (s string) {
 	return s
 }
 
+func ToInt64(value interface{}) (d int64) {
+	val := reflect.ValueOf(value)
+	switch value.(type) {
+	case int, int8, int16, int32, int64:
+		d = val.Int()
+	case uint, uint8, uint16, uint32, uint64:
+		d = int64(val.Uint())
+	default:
+		panic(fmt.Errorf("ToInt64 need numeric not `%T`", value))
+	}
+	return
+}
+
 func snakeString(s string) string {
 	data := make([]byte, 0, len(s)*2)
 	j := false