## Default response class

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

The parameter that defines this is `default_response_class`.

In the example below, **FastAPI** will use `ORJSONResponse` by default, in all *path operations*, instead of `JSONResponse`.

```Python hl_lines="2  4"

        def query_example(
            data: Union[str, None] = Query(
                default=None,
                example="query1",
            ),
        ):
            return data

    @app.get("/query_examples/")
    def query_examples(
        data: Union[str, None] = Query(
            default=None,
            examples=["query1", "query2"],
        ),
    ):
        return data

     *
     * @see #getArtifacts()
     */
    @Nonnull
    Packaging getPackaging();

    /**
     * Returns the project language. It is by default determined by {@link #getPackaging()}.
     *
     * @see #getPackaging()
     */
    @Nonnull
    default Language getLanguage() {
        return getPackaging().language();
    }

    /**

          exempt-pr-labels: "override-stale"
          #Limit the No. of API calls in one run default value is 30.
          operations-per-run: 1000
          days-before-issue-stale: 7
          days-before-issue-close: 7
          stale-issue-label: "stale"
          # reason for closed the issue default value is not_planned
          close-issue-reason: completed
          # List of labels to remove when issues/PRs unstale. 

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Union[str, None] = Body(default=None),
    size: Union[int, None] = Body(default=None),
):
    if item_id in items:
        item = items[item_id]
        item["name"] = name
        item["size"] = size
        return item
    else:

///

## Override the default exception handlers

**FastAPI** has some default exception handlers.

These handlers are in charge of returning the default JSON responses when you `raise` an `HTTPException` and when the request has invalid data.

You can override these exception handlers with your own.

    return implied;
  }

  @Retention(RetentionPolicy.RUNTIME)
  @Inherited
  @TesterAnnotation
  public @interface Require {
    public abstract SetFeature[] value() default {};

    public abstract SetFeature[] absent() default {};
  }

from sqlmodel import Field, Session, SQLModel, create_engine, select


class Hero(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    age: int | None = Field(default=None, index=True)
    secret_name: str


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"

connect_args = {"check_same_thread": False}

from sqlmodel import Field, Session, SQLModel, create_engine, select


class HeroBase(SQLModel):
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)


class Hero(HeroBase, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    secret_name: str


class HeroPublic(HeroBase):
    id: int


class HeroCreate(HeroBase):
    secret_name: str

 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingSortedSetMultimap}.
 *
 * @author Kurt Alfred Kluever