> For the complete documentation index, see [llms.txt](https://jen-hsuan-hsieh.gitbook.io/asp-net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jen-hsuan-hsieh.gitbook.io/asp-net/chapter3rest-api-design-development-and-management/33designing-rest-api/333implementing-rest-api-crud-operations.md). # 3.3.3.Implementing REST API CRUD operations * [Uniform Interface Constraint](https://jenhsuan.gitbooks.io/asp-net/content/chapter3rest-api-design-development-and-management/32rest-api-architectural-constraints/323uniform-interface.html) has 3 parts: * 1.HTTP method, HTTP協議語句 (Protocol statement) * 2.HTTP status code * 3.Representation formats * HTTP method * HTTP Verbs/ Methods = CRUD * HTTP status code * All HTTP responses have a 3 digit status code * 1xx: Informal e.g., 100: Continue * 2xx: Success e.g., 200: OK * 3xx: Redirection e.g., 307: Temporary redirect * 4xx: Client error e.g., 404: Not found * 5xx: Server error e.g., 500: Internal server error * [RFC2616](https://www.w3.org/Protocols/rfc2616/rfc2616.html) * \[POST] * 基於給定的訊息, 在當前資源的下一層創建新的資源 * e.g., /vacations, /vacations/{id}/reviews * 不符合冪等性 * 類型1: POST-to-append * 在當前資源的下一層創建新的資源 * 類型2: overloaded POST * "向數據處理流程提供例如表單提交結果的數據塊" * 不僅被用作創建新的資源, 也被用於傳輸任何形式的變化, 他將PUT, DELETE, PATCH, LINK, UNLINK所有的方法混合成一個方法 * Response * 狀態碼 * Sucesss: e.g., code = 201 * May return a link (id) to new resource in Location header e.g., Location: * May return a new object * Failure: * 4xx Bad request e.g., 400 missing required field * 5xx Issue in processing e.g., 503 database unreachable * 響應表頭 (response header) * content type * Content-Type * application/vnd.collection+json * \[GET] * 從資源處獲取一個[表述(representation)](https://jenhsuan.gitbooks.io/asp-net/content/chapter3rest-api-design-development-and-management/31evolution-of-restful-services/312introduction-to-restful-api.html), 並且沒有主觀去改變資源的意圖, 但在現實生活中不能保重GET請求是安全的, 在設計時賦予GET請求重大的副作用是不合理的 * e.g., /vacations, /vacations/{id} * Response * 實體消息體 (entity body) * 狀態碼 * Sucesss: e.g., code = 200 OK * Send back the response requested format e.g., GET * Failure: * 4xx Bad request e.g., 404 Resource not found * 5xx Issue in processing e.g., 500 Internal server error * 響應表頭 (response header) * content type * \[PUT/PATCH] * 用於修改資源狀態的請求 * PUT * Update all attributes of existing resource - effectively replace * Can also CREATE if client provide ID (not suggested) * PATCH * Modified parts of an existing resource. * e.g., PATCH * 符合冪等性 (Idempotence) * Return * Sucesss: e.g., code = 200 OK, 204 Content, 201 Created * Resource in body of response(optional) * No need to send the link (optional) * \[DELETE] * 銷毀一個資源 * e.g., /vacations, /vacations/{id} * 符合冪等性 (Idempotence) * 發送兩次請求和發送一次請求的響應是一樣的 * Response * 實體消息體 (entity body) * 狀態碼 * Sucesss: * code = 200 OK * May return deleted resource in the response body * code = 204 * No returned content = 204 * Failure: * 4xx Bad request e.g., 404 Resource not found * 5xx Issue in processing e.g., 503 database unreachable * \[OPTIONS] * 獲取這個資源所能響應的HTTP方法列表 * \[LINK] * \[UNLINK] * Resource representation * Request * Query parameters * e.g., /search?q=iphone\&format=xml * HTTP Header accepts * e.g., Accepts: application/json * Resource Format Suffix * e.g., /programmes/schedules/fm/today.json * Use of HTTP **Accept** header is not so common * Most providers set default format = json * Response * 1.Content-Type * 2.HTTP status code = 415, Requested format not supported * 3.Document * (a) supported formats * (b) how requester specifies