### Tested

* 100% <abbr title="The amount of code that is automatically tested">test coverage</abbr>.
* 100% <abbr title="Python type annotations, with this your editor and external tools can give you better support">type annotated</abbr> code base.

	if err := DB.First(&User{}, "name = ?", user2.Name).Error; err != nil {
		t.Fatalf("Should not find rollbacked nested record")
	}
}

func TestDisabledNestedTransaction(t *testing.T) {
	var (
		user  = *GetUser("transaction-nested", Config{})
		user1 = *GetUser("transaction-nested-1", Config{})
		user2 = *GetUser("transaction-nested-2", Config{})
	)

			"C",
		),
		"C.\n",
	},
	{
		"nested #define",
		lines(
			"#define A #define B THIS",
			"A",
			"B",
		),
		"THIS.\n",
	},
	{
		"nested #define with args",
		lines(
			"#define A #define B(x) x",
			"A",
			"B(THIS)",
		),
		"THIS.\n",
	},
	/* This one fails. See comment in Slice.Col.
	{
		"nested #define with args",
		lines(

				"88d4266fd4e6338d13b845fcf289579d209c897823b9217da3e161936f031589",
			},
		},
		{
			desc:       "Nested hash reader NewReader() should merge.",
			src:        mustReader(t, bytes.NewReader([]byte("abcd")), 4, "", "", 4),
			size:       4,
			actualSize: 4,
		},
		{
			desc:       "Incorrect sha256, nested",
			src:        mustReader(t, bytes.NewReader([]byte("abcd")), 4, "", "", 4),
			size:       4,
			actualSize: 4,

	users := []User{
		{
			Name: "nested-joins-1",
			Manager: &User{
				Name: "nested-joins-manager-1",
				Company: Company{
					Name: "nested-joins-manager-company-1",
				},
				NamedPet: &Pet{
					Name: "nested-joins-manager-namepet-1",
					Toy: Toy{
						Name: "nested-joins-manager-namepet-toy-1",
					},
				},
			},

			wantResult: `{"nested":[[2,3,4],[7,8.5,9]]}`,
		},
		{
			name:       "select-in-combine-and-no",
			query:      `SELECT s.nested from s3object s WHERE (8.5 IN s.nested[*][*]) AND (s.id = 0)`,
			wantResult: ``,
		},
		{
			name:       "select-in-nested-float-no-flat",
			query:      `SELECT s.nested from s3object s WHERE 8.5 IN s.nested[*]`,

		return strconv.FormatUint(v, 10)
	}
	return ""
}

const nestedRelationSplit = "__"

// NestedRelationName nested relationships like `Manager__Company`
func NestedRelationName(prefix, name string) string {
	return prefix + nestedRelationSplit + name
}

// SplitNestedRelationName Split nested relationships to `[]string{"Manager","Company"}`
func SplitNestedRelationName(name string) []string {

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures

You can also combine `dataclasses` with other type annotations to make nested data structures.

In some cases, you might still have to use Pydantic's version of `dataclasses`. For example, if you have errors with the automatically generated API documentation.

							}
						} else {
							matchedFieldCount[column] = 1
						}
					} else if names := utils.SplitNestedRelationName(column); len(names) > 1 { // has nested relation
						if rel, ok := sch.Relationships.Relations[names[0]]; ok {
							subNameCount := len(names)
							// nested relation fields
							relFields := make([]*schema.Field, 0, subNameCount-1)
							relFields = append(relFields, rel.Field)

It can't handle nested models very well. So, if the JSON body in the request is a JSON object that has inner fields that in turn are nested JSON objects, it cannot be properly documented and validated.

/// check | "Inspired **FastAPI** to"

Use Python types to have great editor support.