# FlareDB SQL Layer CRUD Example

This example demonstrates the basic CRUD operations using the FlareDB SQL layer.

## Prerequisites

1. A running FlareDB server on `127.0.0.1:8001`
2. Rust toolchain installed

## What This Example Does

The example performs the following operations:

1. **CREATE TABLE**: Creates a `users` table with columns (id, name, email, active)
2. **INSERT**: Inserts 4 sample users into the table
3. **SELECT \***: Queries all users
4. **SELECT with WHERE**: Queries only active users
5. **SELECT specific user**: Queries a single user by ID
6. **DROP TABLE**: Cleans up by dropping the table

## Running the Example

```bash
# Navigate to the example directory
cd docs/por/T037-flaredb-sql-layer/example-crud

# Run the example
cargo run --bin crud-example
```

## Expected Output

```
=== FlareDB SQL Layer CRUD Example ===

Connecting to FlareDB server at 127.0.0.1:8001...
Connected!

Step 1: Creating 'users' table...
✓ DdlSuccess("Table 'users' created")

Step 2: Inserting users...
✓ Inserted: Alice Johnson - DmlSuccess(1)
✓ Inserted: Bob Smith - DmlSuccess(1)
✓ Inserted: Carol White - DmlSuccess(1)
✓ Inserted: Dave Brown - DmlSuccess(1)

Step 3: Querying all users...
✓ Query result:
QueryResult { columns: ["id", "name", "email", "active"], rows: [...] }

Step 4: Querying active users only...
✓ Active users:
QueryResult { columns: ["id", "name", "email", "active"], rows: [...] }

Step 5: Querying user with id=2...
✓ Found user:
QueryResult { columns: ["id", "name", "email", "active"], rows: [...] }

Step 6: Dropping 'users' table...
✓ DdlSuccess("Table 'users' dropped")

=== Example completed ===
```

## Implementation Details

The example uses:
- `flaredb-client`: For connecting to the FlareDB server
- `flaredb-sql`: For executing SQL statements

All operations use strong consistency mode, ensuring ACID properties for SQL operations.

## Supported SQL Statements

Current SQL layer implementation supports:
- `CREATE TABLE` with primary key constraints
- `DROP TABLE`
- `INSERT INTO` with explicit column values
- `SELECT` with column list or `*`
- `WHERE` clause with comparison operators (=, <, >, <=, >=, !=)

## Future Enhancements

Planned features include:
- UPDATE and DELETE statements
- JOIN operations
- Aggregation functions (COUNT, SUM, AVG, etc.)
- ORDER BY and LIMIT clauses
- Indexes for query optimization