In this Prompt Engineering Guide:
- Why "Garbage In, Garbage Out" is literally true
- Rule 1: The Power of Personas ("Act as...")
- Rule 2: Negative Constraints (What not to do)
- Rule 3: Few-Shot Prompting (Giving examples)
- Cheat Sheet: The perfect coding prompt
We have all been there. You ask ChatGPT to write a simple SQL query, and it gives you a paragraph of text, three apologies, and code that doesn't compile. You roll your eyes and say, "AI is overhyped."
The problem isn't the AI. The problem is that you are treating it like a search engine (Google) instead of a junior employee.
To get exactly what you want—whether it's a VB.NET Stored Procedure or a 3D printer review—you need to stop "asking" and start "training." Here is how to master the art of the Prompt.
Rule 1: Assign a Persona
If you just ask "Write code for a login page," the AI averages the entire internet. It gives you generic, mediocre code.
You must tell it Who It Is. This switches the AI's internal context to a specific subset of training data.
Bad Prompt
"Write a function to clean JSON."
Good Prompt
"Act as a Senior .NET Developer. We are using VB.NET WebForms. Write a secure function to clean JSON strings."
Rule 2: The "Negative Constraint"
AI loves to be helpful, often too helpful. It will explain things you already know or use libraries you don't have installed.
You must explicitly tell it what NOT to do. This is often more important than telling it what to do.
- "Do not explain the code. Just give me the function."
- "Do not use Entity Framework. Use raw SQL."
- "Do not use C#. This project is strictly VB.NET."
By narrowing the path, you force the AI into the specific solution you need.
Rule 3: Few-Shot Prompting (The "Example" Trick)
This is the secret weapon. If you want a specific format (like our blog layout with the Bootstrap alert boxes), don't describe it. Paste an example.
In AI research, this is called "Few-Shot Prompting." You give the AI a pattern, and it simply completes the pattern.
Example:
"I need a blog post. Use the following HTML structure for every section:"
<div class="alert alert-info">...</div>
The Ultimate Coding Prompt
Copy this prompt. Save it. Use it whenever you need code for your "Great Meets" projects.
Example: "Act as a Senior Software Architect. We are building a legacy ASP.NET WebForms application in VB.NET.
Constraints:
1. Use standard ADO.NET (SqlDataReader), not Entity Framework.
2. Use Stored Procedures for all data access.
3. Return only the code block. No explanation text.
4. Ensure all SQL parameters are sanitized to prevent injection.
Task: Create a function to insert a new User."
Be very descriptive and tell it what you are looking for exactly. You are training it. Within a single chat. You can control every aspect of the AI's output. If you want docs in HTML tell it you want that format. If you want certain code to be C# tell it.
Remember once you start a new chat you are starting over. Instead of doing that. Ask AI to generate a prompt for everything you are currently working on to be provided to a new chat and just like that you can pick up right where you left off.
Don't be afraid to change the rules. AI loves to talk with other AI's so if you need to generate a picture that is hard to describe ask AI to generate a prompt you can use for the other AI to perform the task.
Conclusion: It's a Tool, Not a Magic Wand
AI is a mirror. If you give it vague, lazy instructions, it reflects vague, lazy answers back at you. If you give it precise, professional constraints, it becomes the best pair-programmer you have ever had.
Share Your Best Prompts!
Have you found a prompt that makes ChatGPT generate perfect SVG icons or write flawless SQL? Share your "System Prompts" in the Coding & AI forum.
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