# SQLite in the Browser with sql.js Run SQLite databases entirely in the browser using WebAssembly. ## Basic Setup ```html 


    


```

## Prepared Statements

```javascript
// Safer way to insert data with parameters
const stmt = db.prepare('INSERT INTO users (name, email) VALUES (?, ?)');
stmt.run(['David', 'david@example.com']);
stmt.free();
```

## Export Database

```javascript
// Export database as a file
function downloadDatabase() {
    const data = db.export();
    const blob = new Blob([data], { type: 'application/x-sqlite3' });
    const url = URL.createObjectURL(blob);

    const a = document.createElement('a');
    a.href = url;
    a.download = 'database.sqlite';
    a.click();

    URL.revokeObjectURL(url);
}
```

## Import Database from File

```javascript
async function loadDatabaseFromFile(file) {
    const SQL = await initSqlJs({
        locateFile: file => `https://cdnjs.cloudflare.com/ajax/libs/sql.js/1.8.0/${file}`
    });

    const arrayBuffer = await file.arrayBuffer();
    db = new SQL.Database(new Uint8Array(arrayBuffer));
}

// Usage with file input
document.getElementById('fileInput').addEventListener('change', async (e) => {
    const file = e.target.files[0];
    if (file) {
        await loadDatabaseFromFile(file);
        console.log('Database loaded!');
    }
});
```

## Use Cases

- Client-side data analysis
- Offline-first applications
- Data exploration tools
- CSV to SQLite converter
- Temporary query playground

## Performance

- Entire database runs in memory
- Fast queries on small to medium datasets
- Can handle databases up to ~100MB efficiently
- Persistence via localStorage or file download