Decimal cannot be converted to type float32

[iv-menshenin]

Scan error on column index 9, name "DISCOUNT": reflect.Value.
Convert: value of type decimal.
Decimal cannot be converted to type float32 on column DISCOUNT"

scanner:

func (f *refScanner) Scan (src interface{}) (err error) {

	defer func(){
		if r := recover(); r != nil {
			if s, ok := r.(string); ok {
				err = errors.New(s + " on column `" + f.ColumnName + "`")
			} else {
				err = errors.New(fmt.Sprintf("<%T>: %s on column `%s`", r, r, f.ColumnName))
			}
		}
	}()

	sv := reflect.ValueOf(src)
	if sv.IsValid() {

		k := sv.Kind()
		if k == reflect.Ptr || k == reflect.Interface {

			if sv.IsNil() {
				return
			}
			sv = sv.Elem()

		}

		if f.Destination.Kind() == reflect.Slice && f.Destination.Type().Elem().Kind() != reflect.Struct {

			f.Destination.Set(sv.Convert(f.Destination.Type()))

		} else
		if f.Destination.Kind() == reflect.Slice {

			// the slice must extends in each iteration
			currCap := f.Destination.Cap()
			currLen := f.RowsCount 			// needed len

			// extends if needed
			if currLen > currCap {
				newCap := (currLen + currCap / 2) + 4
				newSlice := reflect.MakeSlice(f.Destination.Type(), currLen, newCap)
				reflect.Copy(newSlice, *f.Destination)
				f.Destination.Set(newSlice)
			}
			// each iteration, remember
			f.Destination.SetLen(currLen)
			field := f.Destination.Index(f.RowsCount - 1).Field(f.Index)
			if field.Kind() == reflect.ValueOf(&(time.Time{})).Kind() && field.IsNil() {
				field.Set(reflect.New(field.Type().Elem()))
				field = field.Elem()
			}
			field.Set(sv.Convert(field.Type()))

		} else {

			if f.Destination.Kind() == reflect.ValueOf(&(time.Time{})).Kind() && f.Destination.IsNil() {
				f.Destination.Set(reflect.New(f.Destination.Type().Elem()))
				f.Destination.Elem().Set(sv.Convert(f.Destination.Elem().Type()))

			} else {
				f.Destination.Set(sv.Convert(f.Destination.Type()))

			}

		}
		return

	}

	return

}

sql procedure signature:

procedure get_list(
    session char(16) character set octets,
    fltid varchar(64),
    fskip integer,
    fcount integer,
    sorted varchar(10),
    approved boolean
    )returns(   
    created timestamp,
    client_uuid char(16) character set octets,  
    group_uuid char(16) character set octets,
    fullname varchar(64),
    ctype varchar(64),
    pic varchar(64),
    ncountry varchar(64),
    country_code varchar(64),
    ncity varchar(64),   
    city_uuid char(16) character set octets,
    discount numeric(4,2),  
    like_rate numeric(4,2),
    balance numeric(18,4),
    likes int,
    gift int,
    toptags varchar(2048),
    errcode integer,
    err varchar(250)
    );

Struct:

	TApiClientListV100 struct {
		UUID []uint8					`json:"uuid" sql:"CLIENT_UUID"`
		GroupUUID []uint8				`json:"group_uuid" sql:"GROUP_UUID"`
		FullName string					`json:"clientname" sql:"FULLNAME"`
		Type string						`json:"type" sql:"CTYPE"`
		Picture string					`json:"picture" sql:"PIC"`
		Country string					`json:"country" sql:"NCOUNTRY"`
		CountryCode string				`json:"country_code" sql:"COUNTRY_CODE"`
		City string						`json:"city" sql:"NCITY"`
		CityUUID []uint8				`json:"city_uuid" sql:"CITY_UUID"`
		Discount float32				`json:"discount" sql:"DISCOUNT"`
		Balance float32					`json:"balance" sql:"BALANCE"`
		Likes int						`json:"likes" sql:"LIKES"`
		StrTags string					`json:"-" sql:"TOPTAGS"`
		Hashtags []TApiTag100			`json:"tags"`
	}

[iv-menshenin]

It worked well a few months ago (six to seven months)
And brokes after 'git pull'

here is woked fine = bf34760

[iv-menshenin]

and same error with float64
in this commit it works fine = bf34760

[nakagami]

Please use shopspring/decimal now.

I hope to support decimal in Go2.

• proposal: database/sql: define a Decimal decompose interface for decimal packages golang/go#30870
• support decimals: planning denisenkom/go-mssqldb#245