但由于这种用例很常见，FastAPI 为了简便，就直接提供了对它的支持。

///

### 使用表单数据

/// tip | 提示

`OAuth2PasswordRequestForm` 类依赖项的实例没有以空格分隔的长字符串属性 `scope`，但它支持 `scopes` 属性，由已发送的 scope 字符串列表组成。

本例没有使用 `scopes`，但开发者也可以根据需要使用该属性。

///

现在，即可使用表单字段 `username`，从（伪）数据库中获取用户数据。

如果不存在指定用户，则返回错误消息，提示**用户名或密码错误**。

本例使用 `HTTPException` 异常显示此错误：

/**
 * An SPI interface to extend Maven with new enum values for extensible enumerations.
 * <p>
 * Maven uses extensible enumerations to allow plugins and extensions to add new values
 * to various categories like languages, scopes, and packaging types. This interface is the
 * base for all providers that register such extensions.
 * <p>
 * Implementations of this interface are discovered through the Java ServiceLoader mechanism.

* Never store plaintext passwords, only password hashes.
* Implement and use well-known cryptographic tools, like pwdlib and JWT tokens, etc.
* Add more granular permission controls with OAuth2 scopes where needed.
* ...etc.

Nevertheless, you might have a very specific use case where you really need to disable the API docs for some environment (e.g. for production) or depending on configurations from environment variables.

	var names1 []string
	DB.Model(&User{}).Where("name like ?", "distinct%").Distinct().Order("name").Pluck("Name", &names1)

	AssertEqual(t, names1, []string{"distinct", "distinct-2", "distinct-3"})

	var names2 []string
	DB.Scopes(func(db *gorm.DB) *gorm.DB {
		return db.Table("users")
	}).Where("name like ?", "distinct%").Order("name").Pluck("name", &names2)
	AssertEqual(t, names2, []string{"distinct", "distinct", "distinct", "distinct-2", "distinct-3"})

      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

     *
     * @param phase
     * @return
     */
    public Lifecycle get(String phase) {
        return getPhaseToLifecycleMap().get(phase);
    }

    /**
     * We use this to map all phases to the lifecycle that contains it. This is used so that a user can specify the
     * phase they want to execute, and we can easily determine what lifecycle we need to run.
     *
     * @return A map of lifecycles, indexed on id

				dst.WriteByte('n')
			case '\r':
				dst.WriteByte('r')
			case '\t':
				dst.WriteByte('t')
			default:
				// This encodes bytes < 0x20 except for \t, \n and \r.
				// If escapeHTML is set, it also escapes <, >, and &
				// because they can lead to security holes when
				// user-controlled strings are rendered into JSON
				// and served to some browsers.
				dst.WriteString(`u00`)
				dst.WriteByte(hexTable[b>>4])

  /**
   * The number of other exception types in the cache of known-good exceptions and the number of
   * other {@code ClassValue} entries for the exception type to be tested. This lets us evaluate
   * whether our solution scales to use with multiple exception types and to whether it is affected
   * by other {@code ClassValue} users. Some of the benchmarked implementations don't use one or
   * both of these mechanisms, so they will be unaffected.
   */

import org.apache.maven.execution.DefaultMavenExecutionResult;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.impl.InternalSession;
import org.apache.maven.impl.resolver.scopes.Maven4ScopeManagerConfiguration;
import org.apache.maven.internal.impl.DefaultLookup;
import org.apache.maven.internal.impl.DefaultSession;
import org.apache.maven.internal.impl.InternalMavenSession;