import static com.google.common.testing.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Sets;
import java.util.Set;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Base class for tests for emulated {@link AbstractFuture} that allow subclasses to swap in a
 * different "source Future" for {@link AbstractFuture#setFuture} calls.
 */
@GwtCompatible(emulated = true)

E esses modelos estão compartilhando muitos dos dados e duplicando nomes e tipos de atributos.

Nós poderíamos fazer melhor.

Podemos declarar um modelo `UserBase` que serve como base para nossos outros modelos. E então podemos fazer subclasses desse modelo que herdam seus atributos (declarações de tipo, validação, etc.).

Toda conversão de dados, validação, documentação, etc. ainda funcionará normalmente.

from typing import Optional

from fastapi.openapi.models import APIKey, APIKeyIn
from fastapi.security.base import SecurityBase
from starlette.exceptions import HTTPException
from starlette.requests import Request
from starlette.status import HTTP_403_FORBIDDEN
from typing_extensions import Annotated, Doc


class APIKeyBase(SecurityBase):
    pass


class APIKeyQuery(APIKeyBase):
    """

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Base class for testers of classes (including {@link Collection} and {@link java.util.Map Map})
 * that contain elements.
 *
 * @param <C> the type of the container
 * @param <E> the type of the container's contents

		return 0, err
	}

	// Prepare a temporary directory that will be cleaned up at the end.
	// Binary names can conflict.
	// E.g. template.test from the {html,text}/template packages.
	binName := filepath.Base(os.Args[1])
	deviceGotmp := fmt.Sprintf(deviceRoot+"/%s-%d", binName, os.Getpid())
	deviceGopath := deviceGotmp + "/gopath"
	defer adb("exec-out", "rm", "-rf", deviceGotmp) // Clean up.

	SRAW	$1, X6					// 1b531340

	// 4.3: Load and Store Instructions (RV64I)
	LD	(X5), X6				// 03b30200
	LD	4(X5), X6				// 03b34200
	SD	X5, (X6)				// 23305300
	SD	X5, 4(X6)				// 23325300

	// 8.1: Base Counters and Timers (Zicntr)
	RDCYCLE		X5				// f32200c0
	RDTIME		X5				// f32210c0
	RDINSTRET	X5				// f32220c0

	// 13.1: Multiplication Operations
	MUL	X5, X6, X7				// b3035302

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.hash;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import com.google.errorprone.annotations.Immutable;
import java.security.Key;
import java.util.ArrayList;
import java.util.Arrays;

 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.util.concurrent.ExecutionSequencer.RunningState.CANCELLED;

{!../../docs_src/sql_databases/sql_app/database.py!}
```

### 创建一个`Base`类

现在我们将使用`declarative_base()`返回一个类。

稍后我们将继承这个类，来创建每个数据库模型或类（ORM 模型）：

```Python hl_lines="13"
{!../../docs_src/sql_databases/sql_app/database.py!}
```

## 创建数据库模型

现在让我们看看文件`sql_app/models.py`。

### 用`Base`类来创建 SQLAlchemy 模型

我们将使用我们之前创建的`Base`类来创建 SQLAlchemy 模型。

/// tip