When I started building REST APIs in Spring Boot, I thought this:
PUT = update
PATCH = update
DELETE = delete
Simple.
But the moment I started building real APIs, things broke.
- PUT updated more than it should
- PATCH behaved unexpectedly
- DELETE always returned success — even when nothing was deleted
That’s when I realized I didn’t truly understand PUT, PATCH, and DELETE mappings.
🧠Why These HTTP Methods Matter
In REST APIs, HTTP methods are not just syntax.
They define:
- API behavior
- Client expectations
- Data integrity
- Error handling
Using the wrong method can make your API confusing, unreliable, and hard to maintain.
✏️ PUT Mapping — Full Update
PUT is used when you want to replace an entire resource.
Key idea:
PUT expects the complete object, not partial data.
If a field is missing:
- It may be overwritten
- Or reset unintentionally
That’s why PUT must be used carefully.
🧩 PATCH Mapping — Partial Update
PATCH is used when you want to update only specific fields.
Key idea:
PATCH modifies only what is provided, leaving the rest untouched.
This is extremely useful when:
- Updating a single field
- Avoiding accidental data loss
- Designing flexible APIs
Once I understood this difference, my update APIs stopped behaving strangely.
🗑️ DELETE Mapping — Remove a Resource
DELETE is used to remove a resource from the system.
Sounds simple — but here’s where many beginners (including me) go wrong.
Common mistake:
- Always returning success
- Even when the resource doesn’t exist
A good DELETE API should:
- Verify the resource exists
- Return meaningful responses
- Handle errors gracefully
DELETE is not just about removing data — it’s about correct API behavior.
⚠️ The Mistake I Was Making
I used to:
- Use PUT everywhere
- Ignore PATCH completely
- Treat DELETE as a dummy operation
It worked in demos — but failed in real projects.
Understanding intent behind each method changed how I design APIs.
âś… What Changed After I Got This Right
Once I used these mappings correctly:
- APIs became predictable
- Clients trusted responses
- Bugs reduced
- Code felt professional
This is where Spring Boot APIs start to feel production-ready.
🚀 Final Thoughts
PUT, PATCH, and DELETE look simple — until you misuse them.
If you’re learning Spring Boot and your APIs feel:
- Unclear
- Inconsistent
- Hard to debug
Start here.
This understanding is a major step in becoming a backend developer.
This post is part of my learning-in-public journey while exploring Spring Boot and REST API design.
Top comments (0)