diff --git a/convert.go b/convert.go
index 0504bef1..2316ca0b 100644
--- a/convert.go
+++ b/convert.go
@@ -209,10 +209,10 @@ func convertAssign(dest, src interface{}) error {
 		if src == nil {
 			dv.Set(reflect.Zero(dv.Type()))
 			return nil
-		} else {
-			dv.Set(reflect.New(dv.Type().Elem()))
-			return convertAssign(dv.Interface(), src)
 		}
+
+		dv.Set(reflect.New(dv.Type().Elem()))
+		return convertAssign(dv.Interface(), src)
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		s := asString(src)
 		i64, err := strconv.ParseInt(s, 10, dv.Type().Bits())
diff --git a/session_convert.go b/session_convert.go
index f2c949ba..1f9d8aa1 100644
--- a/session_convert.go
+++ b/session_convert.go
@@ -34,27 +34,27 @@ func (session *Session) str2Time(col *core.Column, data string) (outTime time.Ti
 		sd, err := strconv.ParseInt(sdata, 10, 64)
 		if err == nil {
 			x = time.Unix(sd, 0)
-			session.engine.logger.Debugf("time(0) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+			//session.engine.logger.Debugf("time(0) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 		} else {
-			session.engine.logger.Debugf("time(0) err key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+			//session.engine.logger.Debugf("time(0) err key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 		}
 	} else if len(sdata) > 19 && strings.Contains(sdata, "-") {
 		x, err = time.ParseInLocation(time.RFC3339Nano, sdata, parseLoc)
 		session.engine.logger.Debugf("time(1) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 		if err != nil {
 			x, err = time.ParseInLocation("2006-01-02 15:04:05.999999999", sdata, parseLoc)
-			session.engine.logger.Debugf("time(2) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+			//session.engine.logger.Debugf("time(2) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 		}
 		if err != nil {
 			x, err = time.ParseInLocation("2006-01-02 15:04:05.9999999 Z07:00", sdata, parseLoc)
-			session.engine.logger.Debugf("time(3) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+			//session.engine.logger.Debugf("time(3) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 		}
 	} else if len(sdata) == 19 && strings.Contains(sdata, "-") {
 		x, err = time.ParseInLocation("2006-01-02 15:04:05", sdata, parseLoc)
-		session.engine.logger.Debugf("time(4) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+		//session.engine.logger.Debugf("time(4) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 	} else if len(sdata) == 10 && sdata[4] == '-' && sdata[7] == '-' {
 		x, err = time.ParseInLocation("2006-01-02", sdata, parseLoc)
-		session.engine.logger.Debugf("time(5) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+		//session.engine.logger.Debugf("time(5) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 	} else if col.SQLType.Name == core.Time {
 		if strings.Contains(sdata, " ") {
 			ssd := strings.Split(sdata, " ")
@@ -68,7 +68,7 @@ func (session *Session) str2Time(col *core.Column, data string) (outTime time.Ti
 
 		st := fmt.Sprintf("2006-01-02 %v", sdata)
 		x, err = time.ParseInLocation("2006-01-02 15:04:05", st, parseLoc)
-		session.engine.logger.Debugf("time(6) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
+		//session.engine.logger.Debugf("time(6) key[%v]: %+v | sdata: [%v]\n", col.FieldName, x, sdata)
 	} else {
 		outErr = fmt.Errorf("unsupported time format %v", sdata)
 		return