sample

file.go

// GroupByUserAndType : grouping cashback by userId and type
func (service *App) GroupByUserAndType(ctx context.Context, params ...QueryFilter) ([]*SumCashback, error) {
	queryable, ok := data.QueryableFromContext(ctx)
	if !ok {
		queryable = service.queryable
	}
	where, args := BuildFilter(params...)
	statement := fmt.Sprintf(`
		SELECT "userId", SUM(amount) AS "amount", "type"
		FROM "%s" %s GROUP BY "userId", "type";
	`, TableName, where)
	rows, errSelect := queryable.Query(statement, args...)
	if errSelect != nil {
		return nil, errSelect
	}

	defer rows.Close()

	var records []*SumCashback
	for rows.Next() {
		sumCashback := &SumCashback{}
		err := rows.Scan(&sumCashback.UserID, &sumCashback.Amount, &sumCashback.Type)
		if err != nil {
			return nil, err
		}
		records = append(records, sumCashback)
	}

	return records, nil
}