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.

// for example: one goroutine found error and just close the database, and others are executing SQL
// this test making sure that the gorm would not get a Segmentation Fault,
// and the only error cause by this is using a closed Stmt or gorm.ErrInvalidDB
// and all of the goroutine must got gorm.ErrInvalidDB after database close
func TestPreparedStmtConcurrentClose(t *testing.T) {

# databaseInfoMap: (Required)
#
# The database information for the tasks of DBFlute.
# You should specify before your first generating.
#
# o driver   -- The class name of JDBC-Driver.
# o url      -- The URL for connecting database.
# o schema   -- The schema name.
# o user     -- The database user name.
# o password -- The database password.
# o propertiesMap -- The properties that depends on the database.

    #   [true]
    #     Generate the method that depends on the database. e.g. cb.lockWithRR() at DB2.
    #
    #; isAvailableDatabaseDependency = false
    # - - - - - - - - - -/

    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    # o isAvailableDatabaseNativeJDBC: (NotRequired - Default false)
    #   [true]
    #     Use classes of database native JDBC on generated classes to get best performances of DB access.

use internally only data that doesn't depend on the resources of dependencies with `yield`.

For example, instead of using the same database session, you would create a new database session inside of the background task, and you would obtain the objects from the database using this new session. And then instead of passing the object from the database as a parameter to the background task function, you would pass the ID of that object and then obtain the object again inside the background...

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

And the spec says that the fields have to be named like that. So `user-name` or `email` wouldn't work.

But don't worry, you can show it as you wish to your final users in the frontend.

And your database models can use any other names you want.

But for the login *path operation*, we need to use these names to be compatible with the spec (and be able to, for example, use the integrated API documentation system).

map:{
    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    # o database: (Required)
    #  This is the target database, only considered when generating
    #  the SQL for your DBFlute project.
    #  Your possible choices are:
    #
    #    mysql, postgresql, oracle, db2, sqlserver,
    #    h2, derby, (sqlite, firebird, msaccess)
    #
    ; database = h2
    # - - - - - - - - - -/

Directory for library extension

If you use a database that DBFlute does not have its JDBC driver,
put your own JDBC driver for the database here.

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