### Ler Heroes { #read-heroes }

Podemos **ler** `Hero`s do banco de dados usando um `select()`. Podemos incluir um `limit` e `offset` para paginar os resultados.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[48:55] hl[51:52,54] *}

### Ler um Único Hero { #read-one-hero }

	const bucketMetadataRefresh = 15 * time.Minute

	sleeper := newDynamicSleeper(2, 150*time.Millisecond, false)

	t := time.NewTimer(bucketMetadataRefresh)
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			buckets, err := sys.objAPI.ListBuckets(ctx, BucketOptions{NoMetadata: true})
			if err != nil {
				internalLogIf(ctx, err, logger.WarningKind)
				break

		defer timer.Stop()

		var (
			quit     bool
			traceMsg string
			notify   bool // if status changed, notify nodes to reload rebalance metadata
		)

		for {
			select {
			case rebalErr := <-doneCh:
				quit = true
				notify = true
				now := time.Now()
				var status rebalStatus

				switch {
				case errors.Is(rebalErr, context.Canceled):

		// Retry infinitely on Kubernetes and Docker swarm.
		// This is needed as the remote hosts are sometime
		// not available immediately.
		select {
		case <-globalOSSignalCh:
			return fmt.Errorf("The endpoint resolution got interrupted")
		default:
			for i, resolved := range resolvedList {
				if resolved {
					// Continue if host is already resolved.

				}
			}

			switch rv.Kind() {
			case reflect.Map:
				processMap(rv)
			case reflect.Slice, reflect.Array:
				for i := 0; i < rv.Len(); i++ {
					elem := reflect.Indirect(rv.Index(i))
					if elem.Kind() == reflect.Map {
						processMap(elem)
						continue
					}
					appendToFieldValues(elem.Addr())
				}
			case reflect.Struct:
				if !rv.CanAddr() {

	ctx, cancel := context.WithTimeout(ctx, timeout)
	defer cancel()

	c := make(chan ioret[V], 1)
	go func() {
		v, err := work(ctx)
		c <- ioret[V]{val: v, err: err}
	}()

	select {
	case v := <-c:
		return v.val, v.err
	case <-ctx.Done():
		var zero V
		return zero, ctx.Err()
	}
}

// DeadlineWorker implements the deadline/timeout resiliency pattern.

	healthCheckTimeout  = 5 * time.Second
)

func (o *AuthNPlugin) doPeriodicHealthCheck() {
	ticker := time.NewTicker(healthCheckInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			now := time.Now()
			isConnected := o.checkConnectivity(o.shutdownCtx)
			if isConnected {
				o.serviceMetrics.setConnSuccess(now)
			} else {
				o.serviceMetrics.setConnFailure(now)

	}

	// To avoid all MinIO nodes reading the tier config object at the same
	// time.
	t := time.NewTimer(tierCfgRefresh + randInterval())
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			err := config.Reload(ctx, objAPI)
			if err != nil {
				tierLogIf(ctx, err)
			}
		}
		t.Reset(tierCfgRefresh + randInterval())
	}
}

			r.Exists = true
			r.Error = fmt.Sprintf("max size (%d) exceeded: %d", req.MaxSize, len(data))
			select {
			case <-ctx.Done():
				return ctx.Err()
			case resp <- r:
				continue
			}
		}
		found++
		r.Exists = true
		r.Data = data
		r.Modtime = mt
		select {
		case <-ctx.Done():
			return ctx.Err()
		case resp <- r:
		}

	// down `ch`
	go func() {
		for {
		outerLoop:
			watchCh := ies.client.Watch(ctx,
				keyPath, etcd.WithPrefix(), etcd.WithKeysOnly())

			for {
				select {
				case <-ctx.Done():
					return
				case watchResp, ok := <-watchCh:
					if !ok {
						time.Sleep(1 * time.Second)
						// Upon an error on watch channel
						// re-init the watch channel.