main.py

from fastapi import FastAPI, HTTPException
import duckdb
import pandas as pd
import os
app = FastAPI()

# Kết nối đến DuckDB file (hoặc dùng ':memory:')
conn = duckdb.connect("my_database.duckdb")

@app.get("/")
def read_root():
    return {"message": "DuckDB API đang chạy"}

@app.post("/insert/")
def insert_data(name: str, age: int):
    try:
        conn.execute("CREATE TABLE IF NOT EXISTS users (name TEXT, age INTEGER)")
        conn.execute("INSERT INTO users VALUES (?, ?)", (name, age))
        return {"status": "OK"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e
    
@app.get("/save_parquet/")
def save_parquet():
    try:
        df = conn.execute("SELECT * FROM users").fetchdf()
        # create data directory if it doesn't exist
        if not os.path.exists("./data"):
            os.makedirs("./data")
        df.to_parquet("./data/users.parquet")
        return {"status": "Parquet file saved"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e
@app.get("/load_parquet/")
def load_parquet():
    try:
        df = pd.read_parquet("./data/users.parquet")
        # get and return data 
        return df.to_dict(orient="records")
    except FileNotFoundError as e:
        raise HTTPException(status_code=404, detail="Parquet file not found") from e

@app.get("/users/")
def get_users():
    try:
        df = conn.execute("SELECT * FROM users").fetchdf()
        return df.to_dict(orient="records")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e

@app.get("/user/{name}")
def get_user(name: str):
    try:
        df = conn.execute("SELECT * FROM users WHERE name = ?", (name,)).fetchdf()
        if df.empty:
            raise HTTPException(status_code=404, detail="User not found")
        return df.to_dict(orient="records")[0]
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e 
    
@app.delete("/user/{name}")
def delete_user(name: str):
    try:
        result = conn.execute("DELETE FROM users WHERE name = ?", (name,)).rowcount
        if result == 0:
            raise HTTPException(status_code=404, detail="User not found")
        return {"status": "User deleted"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e
@app.put("/user/{name}")
def update_user(name: str, age: int):
    try:
        result = conn.execute("UPDATE users SET age = ? WHERE name = ?", (age, name)).rowcount
        if result == 0:
            raise HTTPException(status_code=404, detail="User not found")
        return {"status": "User updated"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e)) from e
    
def main():
    import uvicorn
    uvicorn.run(app, host="127.0.0.1", port=8000)
if __name__ == "__main__":
    main()