在python中的查询中间追加字符串

Question

我试图在python中构建一个查询，我正在寻找一种在字符串中间附加WHERE条件的优雅方法：

def get_raw_queryset(frequency=None, where_condition=None):
    qs = "SELECT id, COUNT(*) AS count FROM user_transaction_log " \
         # I WANT TO APPEND A WHERE ONLY IF not None
         if where_condition:
             "WHERE .... = 1" \
         "GROUP BY type , strftime('{0}', datetime) ORDER BY id" \
         .format(frequency)
    return qs

Answer 1

只要您可以安全地评估WHERE字符串，即使where_condition不是字符串，这也会有效：

"SELECT ..." + bool(where_condition) * ("WHERE ...") + "GROUP ..."

我希望您能够非常小心地避免SQL注入。