Golang DB.Query方法代碼示例

func active(d db.DB) ([]*db.Entry, error) {
	if itr, err := d.Query(db.Query{Active: true}); err != nil {
		return nil, err
	} else {
		return db.IteratorEntries(itr)
	}
}

func cmdLs(d db.DB, categoryS string, asc bool) {
	if categories, err := d.Categories(); err != nil {
		fatal(err)
	} else if path, err := d.CategoryPath(ParseCategory(categoryS), false); err != nil {
		fatal(err)
	} else if itr, err := d.Query(db.Query{Asc: asc, CategoryID: path.CategoryID()}); err != nil {
		fatal(err)
	} else {
		FprintIterator(os.Stdout, itr, categories, PrintDefault)
	}
}

// Last returns the last entry or an error.
func Last(d db.DB) (*db.Entry, error) {
	itr, err := d.Query(db.Query{})
	if err != nil {
		return nil, err
	}
	defer itr.Close()
	if entry, err := itr.Next(); err == io.EOF {
		return nil, errors.New("db is empty")
	} else {
		return entry, err
	}
}

// ById returns the entry with the given id, or an error.
func ById(d db.DB, id string) (*db.Entry, error) {
	itr, err := d.Query(db.Query{IDs: []string{id}})
	if err != nil {
		return nil, err
	}
	defer itr.Close()
	if entry, err := itr.Next(); err == io.EOF {
		return nil, fmt.Errorf("entry does not exist: %s", id)
	} else {
		return entry, err
	}
}

// NewSummaryIterator returns a new summary iterator producing summaries for
// the given period and firstDay of the week. If the period is datetime.Day,
// it is is ignored. Callers are required to call Close once they are done
// with the iterator.
func NewSummaryIterator(d db.DB, period datetime.Period, firstDay time.Weekday, now time.Time) (*SummaryIterator, error) {
	entries, err := d.Query(db.Query{})
	if err != nil {
		return nil, err
	}
	return &SummaryIterator{
		now:      now,
		entries:  entries,
		period:   period,
		firstDay: firstDay,
	}, nil
}

func cmdReport(d db.DB, categoryS, periodS, firstDayS string) {
	period, err := datetime.ParsePeriod(periodS)
	if err != nil {
		fatal(err)
	} else if period == datetime.Day {
		fatal(errors.New("bad period: day"))
	}
	firstDay, err := datetime.ParseWeekday(firstDayS)
	if err != nil {
		fatal(err)
	}
	path, err := d.CategoryPath(ParseCategory(categoryS), false)
	if err != nil {
		fatal(err)
	}
	entryItr, err := d.Query(db.Query{CategoryID: path.CategoryID()})
	if err != nil {
		fatal(err)
	}
	defer entryItr.Close()
	entry, err := entryItr.Next()
	if err == io.EOF {
		return
	} else if err != nil {
		fatal(err)
	}
	// @TODO move logic into separate function
	now := time.Now()
	reportItr := datetime.NewIterator(entry.Start, period, false, firstDay)
	report := &Report{Duration: period}
	report.From, report.To = reportItr.Next()
	dayItr := datetime.NewIterator(report.To, datetime.Day, false, firstDay)
	day := &ReportDay{}
	day.From, day.To = dayItr.Next()
	report.Days = append([]*ReportDay{day}, report.Days...)
	noteAssigned := false

outer:
	for {
		var overlap time.Duration
		for {
			overlap = entry.PartialDuration(now, day.From, day.To)
			if overlap > 0 {
				day.Tracked += overlap
				if !noteAssigned {
					note := strings.Trim(entry.Note, "\n")
					if note != "" {
						day.Notes = append([]string{note}, day.Notes...)
					}
					noteAssigned = true
				}
			}
			if !entry.Start.Before(day.From) {
				entry, err = entryItr.Next()
				if err == io.EOF {
					fmt.Fprint(os.Stdout, FormatReport(report))
					break outer
				} else if err != nil {
					fatal(err)
				}
				noteAssigned = false
				continue
			}
			day = &ReportDay{}
			day.From, day.To = dayItr.Next()
			if day.To.Before(report.From) {
				fmt.Fprint(os.Stdout, FormatReport(report))
				report = &Report{Duration: period}
				report.From, report.To = reportItr.Next()
			}
			report.Days = append([]*ReportDay{day}, report.Days...)
		}
	}
}