# ModuleNotFoundError: No module named 'flask_sqlalchemy'

- **ID:** `python/flask-import-error-module`
- **Domain:** python
- **Category:** module_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The required Flask extension is not installed in the current Python environment.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **Install the correct package via pip** (95% success)
   ```
   pip install Flask-SQLAlchemy
   ```
2. **Check if the package is installed and activate correct environment** (90% success)
   ```
   pip list | grep Flask-SQLAlchemy
# or use conda environment
   ```

## Dead Ends

- **Installing the wrong package name** — The package name might be different (e.g., Flask-SQLAlchemy vs flask_sqlalchemy). (70% fail)
- **Installing in the wrong virtual environment** — The environment where the app runs doesn't have the package. (80% fail)