mysql查询字符串 为空

user_input = input("请输入查询条件：")
if not user_input:
    print("查询条件不能为空")
else:
    sql_query = f"SELECT * FROM table_name WHERE column_name = '{user_input}'"
    # 执行 SQL 查询

user_input = input("请输入查询条件：")
if not user_input:
    user_input = "default_value"
sql_query = f"SELECT * FROM table_name WHERE column_name = '{user_input}'"
# 执行 SQL 查询

import mysql.connector

user_input = input("请输入查询条件：")
if not user_input:
    print("查询条件不能为空")
else:
    conn = mysql.connector.connect(user='user', password='password', host='host', database='database')
    cursor = conn.cursor()
    query = "SELECT * FROM table_name WHERE column_name = %s"
    cursor.execute(query, (user_input,))
    results = cursor.fetchall()
    # 处理查询结果