### Create Database Tables on Startup

We will create the database tables when the application starts.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[32:37] hl[35:37] *}

Here we create the tables on an application startup event.

For production you would probably use a migration script that runs before you start your app. 🤓

/// tip

// If an error is returned no goroutines have been started and r.err will have been set.
func (r *PReader) startReaders() {
	r.bufferPool.New = func() interface{} {
		return make([]byte, jsonSplitSize+1024)
	}

	// Create queue
	r.queue = make(chan *queueItem, runtime.GOMAXPROCS(0))
	r.input = make(chan *queueItem, runtime.GOMAXPROCS(0))
	r.readerWg.Add(1)

	// Start splitter
	go func() {
		defer close(r.input)

<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

/// note | "備考"

`uvicorn main:app`は以下を示します:

// globalLockGrid is the global lock grid manager.
var globalLockGrid atomic.Pointer[grid.Manager]

// globalGridStart is a channel that will block startup of grid connections until closed.
var globalGridStart = make(chan struct{})

// globalLockGridStart is a channel that will block startup of lock grid connections until closed.
var globalLockGridStart = make(chan struct{})

              }
            },
            directExecutor());

    // Wait for the first task to be started in the background. It will block until we explicitly
    // stop it.
    blockingCallable.waitForStart();

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    assertThat(future2.isDone()).isFalse();

# Events testen: Hochfahren – Herunterfahren

Wenn Sie in Ihren Tests Ihre Event-Handler (`startup` und `shutdown`) ausführen wollen, können Sie den `TestClient` mit einer `with`-Anweisung verwenden:

```Python hl_lines="9-12  20-24"
{!../../docs_src/app_testing/tutorial003.py!}

        // subsequent call will cancel
        assertThrows(
                TransferCancelledException.class,
                () -> listener.transferStarted(event(session, resource, TransferEvent.EventType.STARTED)));
    }

    @Test
    void handlesAbsentTransferSource() throws InterruptedException, TransferCancelledException {

        then
            arg=$( cygpath --path --ignore --mixed "$arg" )
        fi
        # Roll the args list around exactly as many times as the number of
        # args, so each arg winds up back in the position where it started, but
        # possibly modified.
        #
        # NB: a `for` loop captures its iteration list before it begins, so
        # changing the positional parameters here affects neither the number of

# Testando Eventos: inicialização - encerramento

Quando você precisa que os seus manipuladores de eventos (`startup` e `shutdown`) sejam executados em seus testes, você pode utilizar o `TestClient` usando a instrução `with`:

```Python hl_lines="9-12  20-24"
{!../../docs_src/app_testing/tutorial003.py!}

	rebalStopped
	rebalFailed
)

type rebalanceInfo struct {
	StartTime time.Time   `msg:"startTs"` // Time at which rebalance-start was issued
	EndTime   time.Time   `msg:"stopTs"`  // Time at which rebalance operation completed or rebalance-stop was called
	Status    rebalStatus `msg:"status"`  // Current state of rebalance operation. One of Started|Stopped|Completed|Failed.
}