if db_type == "PostgreSQL":
    connection_string = f"postgresql://{username}:{password}@{host}:{port}/{database}"
elif db_type == "MySQL":
    connection_string = f"mysql+pymysql://{username}:{password}@{host}:{port}/{database}"

engine = create_engine(connection_string)

def create_sqlite_from_uploaded_file(uploaded_file, table_name, sample_size=None):
    # xử lý chuyển đổi, tự động phát hiện dữ liệu, tạo bảng SQLite
    pass

class SQLInsightGenerator:
    def analyze_data(self, dataframe, custom_prompt=None):
        # phân tích ngữ cảnh dữ liệu, tạo insight và đề xuất
        return ai_insights

CREATE TABLE employees (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL,
    department TEXT,
    salary REAL NOT NULL,
    hire_date DATE NOT NULL
);

CREATE TABLE departments (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL,
    budget REAL
);

SELECT e.name, e.salary, d.budget, (e.salary / d.budget * 100) as salary_budget_ratio
FROM employees e 
JOIN departments d ON e.department = d.name
WHERE e.salary > 65000;

if 'query_history' not in st.session_state:
    st.session_state.query_history = []

if 'sample_db_path' not in st.session_state:
    temp_db = tempfile.NamedTemporaryFile(delete=False, suffix='.db')
    st.session_state.sample_db_path = temp_db.name

try:
    with engine.connect() as conn:
        result = conn.execute(text(query))  # Parameterized query
        conn.commit()
except SQLAlchemyError as e:
    st.error(f"SQL Error: {str(e)}")