What is the difference between CRUD and CQRS?

Question

Accepted Answer

**CRUD** — Create, Read, Update, Delete. **CQRS** — Command Query Responsibility Segregation.

**CRUD:**
- Single model for read and write.
- Simple operations.
- Same database for all.
- Good for simple apps.

```
CRUD:
CREATE user → DB
READ user ← DB
UPDATE user → DB
DELETE user → DB
(Same model for all)
```

**CQRS:**
- Separate models for read and write.
- Optimized for each.
- Can use different databases.
- Good for complex systems.

```
CQRS:
Commands → Write Model → Write DB
Queries ← Read Model ← Read DB
(Separate models)
```

**Key differences:**
- **CRUD** — single model.
- **CQRS** — separate models.
- **CRUD** — simple.
- **CQRS** — optimized.

Systems Analyst: What is the difference between CRUD and CQRS?