部门平均工资等级

def solve():
    import sqlite3
    import pandas as pd
    conn = sqlite3.connect(':memory:')
    df = pd.read_csv('https://liangdaima.com/static/data/ds_employees.csv')
    df.to_sql('employees', conn, index=False)
    result = conn.execute('SELECT department, AVG(salary) AS avg_s, CASE WHEN AVG(salary) > 15000 THEN \'高薪部门\' WHEN AVG(salary) > 12000 THEN \'中薪部门\' ELSE \'普通部门\' END AS dept_level FROM employees GROUP BY department').fetchall()
    conn.close()
    return result