# 技巧3：使用引导词，引导模型输出特定内容

在[代码生成场景](/chatgpt-tutorial/ji-chu-pian/ji-ben-shi-yong-chang-jing-shi-yong-ji-qiao/chang-jing-4-wu-zhong-sheng-you-xie-dai-ma.md)里，有一个小技巧，上面提到的案例，其 prompt 还可以继续优化，在 prompt 最后，增加一个代码的引导，告知 AI 我已经将条件描述完了，你可以写代码了。

Better：

```
Create a MySQL query for all students in the Computer Science Department:
Table departments, columns = [DepartmentId, DepartmentName]
Table students, columns = [DepartmentId, StudentId, StudentName]
SELECT
```

在 prompt 的最后增加 SELECT 可以很好地提示 AI 可以写 SQL 代码了。

同样的道理，如果你想让 AI 写 Python 代码，那 import 会是比较好的提示。但需要注意，这个只是告知 AI 可以写代码了，并不能告知 AI 写何种代码，你仍然需要在 prompt 里增加提示，告知 AI 要生成何种语言的代码。

在吴恩达的 ChatGPT Prompt Engineering [课程](https://www.deeplearning.ai/short-courses/chatgpt-prompt-engineering-for-developers/)中，也提到这个技巧，只是在课程中，引导词并不是放在最后，而是在 prompt 里直接说明，让 AI 生成一个 JSON 格式的内容。课程中的例子是这样的（注意这个是 python 代码）：

```
prompt = f"""
Generate a list of three made-up book titles along \
with their authors and genres.
Provide them in JSON format with the following keys:
book_id, title, author, genre.
"""
```

我简单解释下，其关键是在 prompt 里跟 AI 说明，需要 AI 按照 JSON 格式输出内容。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://wiki.aig123.com/chatgpt-tutorial/ji-qiao-pian/ji-qiao-3-shi-yong-yin-dao-ci-yin-dao-mo-xing-shu-chu-te-ding-nei-rong.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.