Question

如何获取这些SQL语句序列？上班？我以前只处理过单select个语句而cursor.execute处理得很好。我现在不确定在这种情况下该怎么做。我得到的错误是format requires a mapping

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格式为％（name）s的参数占位符。

我们还假设它在一个“操作”中支持多个语句。注意：第3个语句（SELECT ... UNION ALL SELECT ...）在结尾处缺少分号。

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一起使用（例如，执行多个INSERT）。

为了便于携带和调试，最好一次做一个四个语句。

使用三引号（以及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;
"""

Answer 2

executemany（）用于对多个参数执行相同的单个语句。

你想要的是另一种方式：只需在每个语句上调用execute（）。

如何在我的情况下使用Executemany？

2 个答案: