Disons que vous déclarez le paramètre `q` comme ayant une longueur minimale de `3`, et une valeur par défaut étant `"fixedquery"` :

{* ../../docs_src/query_params_str_validations/tutorial005.py hl[7] *}

/// note | "Rappel"

Avoir une valeur par défaut rend le paramètre optionnel.

///

## Rendre ce paramètre requis

## Faites appel à `uvicorn`

Dans votre application FastAPI, importez et exécutez directement `uvicorn` :

{* ../../docs_src/debugging/tutorial001.py hl[1,15] *}

### À propos de `__name__ == "__main__"`

Le but principal de `__name__ == "__main__"` est d'avoir du code qui est exécuté lorsque votre fichier est appelé avec :

<div class="termy">

```console
$ python myapp.py

		t.Errorf("no error should happen, but got %v", err)
	}

	if name != "groupby" || total != 60 {
		t.Errorf("name should be groupby, but got %v, total should be 60, but got %v", name, total)
	}

	if err := DB.Model(&User{}).Select("name, sum(age)").Where("name = ?", "groupby").Group("users.name").Row().Scan(&name, &total); err != nil {
		t.Errorf("no error should happen, but got %v", err)
	}

 *    119 : Ignored.
 *    120 : Valid.
 *    121 : Disallowed
 *    122 : Mapped inline to the sequence: [b2].
 *    123 : Mapped inline to the sequence: [b2a].
 *    124 : Mapped inline to the sequence: [b2, b3].
 *    125 : Mapped inline to the sequence: [b2a, b3].
 *    126 : Mapped inline to the sequence: [b2, b3a].
 *    127 : Mapped inline to the sequence: [b2a, b3a].
 *
 * The range goes until the beginning of the next range.

De omgevingsvariabele `PATH` zou er bijvoorbeeld zo uit kunnen zien:

//// tab | Linux, macOS

```plaintext
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
```

Dit betekent dat het systeem naar programma's zoekt in de mappen:

* `/usr/local/bin`
* `/usr/bin`

		t.Errorf("no error should happen when query with embedded struct, but got %v", err)
	} else if egNews.BasePost.Title != "engadget_news" {
		t.Errorf("embedded struct's value should be scanned correctly")
	}

	var egPosts []EngadgetPost
	if err := DB.Order("author_name asc").Find(&egPosts).Error; err != nil {
		t.Fatalf("no error should happen when query with embedded struct, but got %v", err)
	}

    "disallowed ".encodeUtf8(),
    // 2.
    "disallowed_STD3_mapped ".encodeUtf8(),
    // 3.
    "disallowed_STD3_valid ".encodeUtf8(),
    // 4.
    "ignored ".encodeUtf8(),
    // 5.
    "mapped ".encodeUtf8(),
    // 6.
    "valid ".encodeUtf8(),
  )

internal const val TYPE_DEVIATION = 0
internal const val TYPE_DISALLOWED = 1
internal const val TYPE_DISALLOWED_STD3_MAPPED = 2

	var result Yasuo
	if err := DB.First(&result, "id = ?", yasuo.ID).Error; err != nil || yasuo.Name != "jinzhu" {
		t.Errorf("No error should happen, but got %v", err)
	}

	if err := DB.Where("id = $1", yasuo.ID).First(&Yasuo{}).Error; err != nil || yasuo.Name != "jinzhu" {
		t.Errorf("No error should happen, but got %v", err)
	}

	yasuo.Name = "jinzhu1"
	if err := DB.Save(&yasuo).Error; err != nil {

	DB.Migrator().DropTable(adaptorSerializerModel(&SerializerStruct{}))
	if err := DB.Migrator().AutoMigrate(adaptorSerializerModel(&SerializerStruct{})); err != nil {
		t.Fatalf("no error should happen when migrate scanner, valuer struct, got error %v", err)
	}

	createdAt := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
	updatedAt := createdAt.Unix()

	data := SerializerStruct{

 * with the range (if any) that contains a specified key.
 *
 * <p>In contrast to {@link RangeSet}, no "coalescing" is done of {@linkplain
 * Range#isConnected(Range) connected} ranges, even if they are mapped to the same value.
 *
 * @author Louis Wasserman
 * @since 14.0
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@DoNotMock("Use ImmutableRangeMap or TreeRangeMap")
@GwtIncompatible