For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder`

Let's imagine that you have a database `fake_db` that only receives JSON compatible data.

For example, it doesn't receive `datetime` objects, as those are not compatible with JSON.

Being able to use asynchronous functions in your tests could be useful, for example, when you're querying your database asynchronously. Imagine you want to test sending requests to your FastAPI application and then verify that your backend successfully wrote the correct data in the database, while using an async database library.

Let's look at how we can make that work.

## pytest.mark.anyio

So, you would be able to, for example, share the same data from a Django application in a database with a FastAPI application. Or gradually migrate a Django application using the same database.

And your users would be able to login from your Django app or from your **FastAPI** app, at the same time.

///

## Hash and verify the passwords

 * under the License.
 */
package org.apache.maven.settings.building;

import org.apache.maven.building.Source;

/**
 * Provides access to the contents of settings independently of the backing store (e.g. file system, database, memory).
 *
 *
 * @deprecated instead use {@link Source}
 */
@Deprecated

This can be very useful for setting up **resources** that you need to use for the whole app, and that are **shared** among requests, and/or that you need to **clean up** afterwards. For example, a database connection pool, or loading a shared machine learning model.

## Use Case

Let's start with an example **use case** and then see how to solve it with this.

 */
package org.apache.maven.building;

import java.io.IOException;
import java.io.InputStream;

/**
 * Provides access to the contents of a source independently of the backing store (e.g. file system, database, memory).
 *
 */
public interface Source {

    /**
     * Gets a byte stream to the source contents. Closing the returned stream is the responsibility of the caller.
     *

 * under the License.
 */
package org.apache.maven.model.building;

import org.apache.maven.building.Source;

/**
 * Provides access to the contents of a POM independently of the backing store (e.g. file system, database, memory).
 * <p>
 * This interface does not support loading of parent POM(s) from the same backing store, integrators are strongly
 * encouraged to implement {@link ModelSource2} instead of implementing this interface directly.

    * `200` is the default status code, which means everything was "OK".
    * Another example would be `201`, "Created". It is commonly used after creating a new record in the database.
    * A special case is `204`, "No Content".  This response is used when there is no content to return to the client, and so the response must not have a body.

 * under the License.
 */
package org.apache.maven.model.building;

import java.net.URI;

/**
 * Provides access to the contents of a POM independently of the backing store (e.g. file system, database, memory).
 * <p>
 * Unlike {@link ModelSource}, this interface supports loading of parent POM(s) from the same backing store and allows

You will see examples of this in the next chapters, about relational and NoSQL databases, security, etc.

## **FastAPI** compatibility

The simplicity of the dependency injection system makes **FastAPI** compatible with:

* all the relational databases
* NoSQL databases
* external packages
* external APIs
* authentication and authorization systems
* API usage monitoring systems