Go Xorm Sql Update操作（int型设置为0）

row, err := session.Cols("a").Update(request, models.m{UserId: request.UserId})

a列要更改为int 0时，这样写，update第一个参数是更改的值，第二个参数是约束条件：

// Update records, bean's non-empty fields are updated contents,
// condiBean' non-empty filds are conditions
// CAUTION:
//        1.bool will defaultly be updated content nor conditions
//         You should call UseBool if you have bool to use.
//        2.float32 & float64 may be not inexact as conditions
func (session *Session) Update(bean interface{}, condiBean ...interface{}) (int64, error) {