# Return a Response Directly { #return-a-response-directly }

When you create a **FastAPI** *path operation* you can normally return any data from it: a `dict`, a `list`, a Pydantic model, a database model, etc.

By default, **FastAPI** would automatically convert that return value to JSON using the `jsonable_encoder` explained in [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank}.

package tests_test

import (
	"database/sql"
	"testing"
	"time"

	"gorm.io/gorm"
	. "gorm.io/gorm/utils/tests"
)

func TestUpdateHasOne(t *testing.T) {
	user := *GetUser("update-has-one", Config{})

	if err := DB.Create(&user).Error; err != nil {
		t.Fatalf("errors happened when create: %v", err)
	}

	user.Account = Account{Number: "account-has-one-association"}

	if err := DB.Save(&user).Error; err != nil {

///

For example, this custom validator checks that the item ID starts with `isbn-` for an <abbr title="ISBN means International Standard Book Number">ISBN</abbr> book number or with `imdb-` for an <abbr title="IMDB (Internet Movie Database) is a website with information about movies">IMDB</abbr> movie URL ID:

{* ../../docs_src/query_params_str_validations/tutorial015_an_py310.py hl[5,16:19,24] *}

/// info

    * Mümkün olduğu kadar modüler yapılmıştır, bu nedenle kutudan çıktığı gibi çalışır, ancak Vue CLI ile yeniden oluşturabilir veya ihtiyaç duyduğunuz şekilde oluşturabilir ve istediğinizi yeniden kullanabilirsiniz.
* **PGAdmin** PostgreSQL database admin tool'u, PHPMyAdmin ve MySQL ile kolayca değiştirilebilir.
* **Flower** ile Celery job'larını monitörleme.

      """.trimMargin(),
    )
    assertThat(callbacks.remove()).isEqualTo(22L)
  }

  @Test
  fun namePrefixIgnored() {
    consumeEvents(
      """
      |data: a
      |eventually
      |database
      |identity
      |retrying
      |
      |
      """.trimMargin(),
    )
    assertThat(callbacks.remove()).isEqualTo(Event(null, null, "a"))
  }

  @Test

To achieve this, you will normally have a **separate program** that would make sure your application is run on startup. And in many cases, it would also make sure other components or applications are also run, for example, a database.

### Example Tools to Run at Startup { #example-tools-to-run-at-startup }

Some examples of the tools that can do this job are:

* Docker
* Kubernetes
* Docker Compose
* Docker in Swarm Mode

 *  Fix: Don't leak file handles when a cache disk write fails.

 *  Fix: Don't hang when the public suffix database cannot be loaded. We had a bug where a failure
    reading the public suffix database would cause subsequent reads to hang when they should have
    crashed.

 *  Fix: Avoid `InetAddress.getCanonicalHostName()` in MockWebServer. This avoids problems if the

* the shutdown event
* the lifespan event

* the handler
* the event handler
* the exception handler
* to handle

* the model
* the Pydantic model
* the data model
* the database model
* the form model
* the model object

* the class
* the base class
* the parent class
* the subclass
* the child class
* the sibling class
* the class method

* the header

In many cases your application could need some external settings or configurations, for example secret keys, database credentials, credentials for email services, etc.

Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

/// tip

 * hostnames (e.g., www.example.com and example.com).</p>
 */
public class DuplicateHostService extends FessAppService {

    /**
     * DBFlute behavior for duplicate host operations.
     * Provides database access methods for DuplicateHost entities.
     */
    @Resource
    protected DuplicateHostBhv duplicateHostBhv;

    /**
     * Fess configuration containing application settings.