python - 在我的情况下如何使用 Executemany？

Question

如何获得这些 SQL 语句序列？上类？我以前只处理过单个 select 语句，而 cursor.execute 工作得很好。我现在不知道在这种情况下该怎么办。我收到的错误是格式需要映射

args =  {
        "timepattern" : timepattern,
        "datestart_int" : datestart_int,
        "dateend_int" : dateend_int
        }
sql = ( "CREATE TEMPORARY TABLE cohort_users (user_id INTEGER);                                "
            "INSERT INTO cohort_users (user_id)                                                    "
            "SELECT id FROM users WHERE registered_at BETWEEN %(datestart_int)s AND %(dateend_int)s;                        "
            "SELECT 1, FROM_UNIXTIME(%(dateend_int)s, %(timepattern)s)                                                    "
            "UNION ALL                                                                            "
            "SELECT (COUNT(DISTINCT x.user_id)/(SELECT COUNT(1) FROM cohort_users)),             "
            "        FROM_UNIXTIME((%(dateend_int)s + (7 * 24 * 60 * 60)), %(timepattern)s)                                "
            "FROM cohort_users z INNER JOIN actions x ON x.user_id = z.id                        "
            "WHERE x.did_at BETWEEN (%(datestart_int)s + (7 * 24 * 60 * 60)) AND (%(dateend_int)s + (7 * 24 * 60 * 60))        "
            "DROP TABLE cohort_users;                                                            "
            )

cursor.executemany(sql,args)

Answer 1

假设您的数据库软件支持 %(name)s 形式的参数占位符。

我们还假设它支持一个“操作”中的多个语句。注意:第三条语句(SELECT ... UNION ALL SELECT ...)末尾缺少分号。

在这种情况下，您需要做的就是使用 cursor.execute(sql, args) ... executemany() 与一系列 args (例如执行多个 INSERT)。

为了可移植性和易于调试，最好一次执行四个语句。

使用三引号(和结构化缩进而不是宽缩进)将使您的 SQL 更易于阅读:

sql = """
CREATE TEMPORARY TABLE cohort_users (user_id INTEGER);   

INSERT INTO cohort_users (user_id)
    SELECT id
        FROM users
        WHERE registered_at BETWEEN %(datestart_int)s AND %(dateend_int)s
    ;

SELECT  1, FROM_UNIXTIME(%(dateend_int)s, %(timepattern)s)
UNION ALL
SELECT  (COUNT(DISTINCT x.user_id)/(SELECT COUNT(1) FROM cohort_users)), 
        FROM_UNIXTIME((%(dateend_int)s + (7 * 24 * 60 * 60)), (timepattern)s)
    FROM cohort_users z
    INNER JOIN actions x ON x.user_id = z.id
    WHERE x.did_at BETWEEN (%(datestart_int)s + (7 * 24 * 60 * 60))
    AND (%(dateend_int)s + (7 * 24 * 60 * 60))
    ;

DROP TABLE cohort_users;
"""