“中间件”基本上是一个对每个请求都执行的函数，其中一些代码在端点函数之前执行，另一些代码在端点函数之后执行。

### 创建中间件

我们要添加的中间件（只是一个函数）将为每个请求创建一个新的 SQLAlchemy`SessionLocal`，将其添加到请求中，然后在请求完成后关闭它。

//// tab | Python 3.9+

```Python hl_lines="12-20"
{!> ../../docs_src/sql_databases/sql_app_py39/alt_main.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="14-22"
{!> ../../docs_src/sql_databases/sql_app/alt_main.py!}
```

		{"test-bucket-list-object", "Asia", "A", "", 1, resultCases[4], nil, true},
		// Setting a non-existing directory to be prefix (12-13).
		{"empty-bucket", "europe/france/", "", "", 1, ListObjectsInfo{}, nil, true},
		{"empty-bucket", "africa/tunisia/", "", "", 1, ListObjectsInfo{}, nil, true},

Type","ajaxHandleResponses","conv2","current","conv","dataFilter","throws","ajaxConvert","getJSON","getScript","text script","wrapAll","firstElementChild","wrapInner","htmlIsFunction","unwrap","visible","xhr","XMLHttpRequest","xhrSuccessStatus","0","1223","xhrSupported","cors","errorCallback","open","username","xhrFields","onload","onerror","onabort","ontimeout","onreadystatechange","responseType","responseText","binary","scriptAttrs","charset","scriptCharset","evt","oldCallbacks","rjsonp","json...

- Modify DNS-1123 error messages to indicate that RFC 1123 is not followed exactly ([#94182](https://github.com/kubernetes/kubernetes/pull/94182), [@mattfenwick](https://github.com/mattfenwick)) [SIG API Machinery, Apps, Auth, Network and Node]

  - [beta] StatefulSets allow workloads that require persistent identity or per-instance storage to be created and managed on Kubernetes. ([docs](http://kubernetes.io/docs/concepts/abstractions/controllers/statefulsets/))...

Type","ajaxHandleResponses","conv2","current","conv","dataFilter","throws","ajaxConvert","getJSON","getScript","text script","wrapAll","firstElementChild","wrapInner","htmlIsFunction","unwrap","visible","xhr","XMLHttpRequest","xhrSuccessStatus","0","1223","xhrSupported","cors","errorCallback","open","username","xhrFields","onload","onerror","onabort","ontimeout","onreadystatechange","responseType","responseText","binary","scriptAttrs","charset","scriptCharset","evt","oldCallbacks","rjsonp","json...

* Restored the pre-1.10 behavior of the openstack cloud provider, which uses the instance name as the Kubernetes Node name. This requires instances be named with RFC-1123 compatible names. ([#63903](https://github.com/kubernetes/kubernetes/pull/63903), [@liggitt](https://github.com/liggitt))

* Restores the pre-1.10 behavior of the openstack cloud provider which uses the instance name as the Kubernetes Node name. This requires instances be named with RFC-1123 compatible names. ([#63903](https://github.com/kubernetes/kubernetes/pull/63903), [@liggitt](https://github.com/liggitt))

  - [Changelog since v1.12.3](#changelog-since-v1123)
    - [Action Required](#action-required)
    - [Other notable changes](#other-notable-changes-6)
- [v1.12.3](#v1123)
  - [Downloads for v1.12.3](#downloads-for-v1123)
    - [Client Binaries](#client-binaries-7)
    - [Server Binaries](#server-binaries-7)
    - [Node Binaries](#node-binaries-7)
  - [Changelog since v1.12.2](#changelog-since-v1122)

	ADCQ (R11), DX                          // 491313
	ADCQ (BX), R11                          // 4c131b
	ADCQ (R11), R11                         // 4d131b
	ADCB (BX), DL                           // 1213
	ADCB (R11), DL                          // 411213
	ADCB (BX), R11                          // 44121b
	ADCB (R11), R11                         // 45121b
	ADCXL (BX), DX                          // 660f38f613