![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

## Build a Docker Image with a Single-File FastAPI { #build-a-docker-image-with-a-single-file-fastapi }

If your FastAPI is a single file, for example, `main.py` without an `./app` directory, your file structure could look like this:

```
.
├── Dockerfile
├── main.py
└── requirements.txt

        testUser.setRoleNames(new String[] {});
        assertFalse(fessUserBean.hasRole("admin"));

        // Test with single role - matching
        testUser.setRoleNames(new String[] { "admin" });
        assertTrue(fessUserBean.hasRole("admin"));

        // Test with single role - not matching
        assertFalse(fessUserBean.hasRole("user"));

        // Test with multiple roles

<div class="termy">

```console
$ pip install sqlmodel
---> 100%
```

</div>

## Create the App with a Single Model { #create-the-app-with-a-single-model }

We'll create the simplest first version of the app with a single **SQLModel** model first.

Later we'll improve it increasing security and versatility with **multiple models** below. 🤓

### Create Models { #create-models }

    public void test_insert_noChains() {
        User user = createTestUser("testuser");
        authenticationManager.insert(user);
        // Should not throw exception even with no chains
    }

    // Test insert with single chain
    @Test
    public void test_insert_singleChain() {
        User user = createTestUser("testuser");
        TestAuthenticationChain chain = new TestAuthenticationChain();
        authenticationManager.addChain(chain);

  )
}

/**
 * If [mapping] qualifies to be encoded as [MappedRange.InlineDelta] return new instance, otherwise null.
 * An [MappedRange.InlineDelta] must be a mapping from a single code-point to a single code-point with a difference
 * that can be represented in 2^18-1.
 */
internal fun inlineDeltaOrNull(mapping: Mapping): MappedRange.InlineDelta? {
  if (mapping.hasSingleSourceCodePoint) {

/// info

`Body` also has all the same extra validation and metadata parameters as `Query`, `Path` and others you will see later.

///

## Embed a single body parameter { #embed-a-single-body-parameter }

Let's say you only have a single `item` body parameter from a Pydantic model `Item`.

By default, **FastAPI** will then expect its body directly.

        ],
        scope: Annotated[
            str,
            Form(),
            Doc(
                """
                A single string with actually several scopes separated by spaces. Each
                scope is also a string.

                For example, a single string with:

                ```python
                "items:read items:write users:read profile openid"
                ````

    @Test
    public void test_putResultDataBody_withObjectArray() {
        TestFessTransformer transformer = new TestFessTransformer();
        Map<String, Object> dataMap = new HashMap<>();

        // First add a single value
        transformer.putResultDataBody(dataMap, "key1", "value1");
        assertEquals("value1", dataMap.get("key1"));

        // Add an array - should merge with existing value

Docker Compose allows defining and running single host, multi-container Docker applications.

        String value;
        String[] result;

        // Single unquoted value
        value = "single";
        result = KuromojiCSVUtil.parse(value);
        assertEquals(1, result.length);
        assertEquals("single", result[0]);

        // Single quoted value - quotes preserved
        value = "\"single quoted\"";
        result = KuromojiCSVUtil.parse(value);