问在Python中运行时“没有这样的函数:地板”，但当我在sqlite3.exe中键入SELECT语句时，它运行时没有问题

EN

sqlite> SELECT "123456789" as ArraySN,
   ...> strftime('%Y-%m-%d %H:%M:%S', datetime(tsecs, 'unixepoch')) as "Date   Time",
   ...> floor(tsecs/1800) * 1800 as "epoch",
   ...> 'W' as "R/W", sum(wsize5) as "16k"
   ...> FROM statvlun GROUP BY "Array SN", "epoch"
   ...> ORDER BY "epoch";

123456789|2021-03-03 05:20:00|1614747600|W|14410640.0
123456789|2021-03-03 05:30:00|1614749400|W|43205476.0
123456789|2021-03-03 06:00:00|1614751200|W|43193768.0
123456789|2021-03-03 06:30:00|1614753000|W|42348397.0
123456789|2021-03-03 07:00:00|1614754800|W|43197724.0
123456789|2021-03-03 07:30:00|1614756600|W|43196195.0
123456789|2021-03-03 08:00:00|1614758400|W|28802535.0

def main():
    sql = """
    SELECT "123456789" as ArraySN,
    strftime('%Y-%m-%d %H:%M:%S', datetime(tsecs, 'unixepoch')) as \"Date   Time\",
    floor(tsecs/1800) * 1800 as "epoch",
    'W' as "R/W", sum(wsize5) as "16k"
    FROM statvlun GROUP BY "Array SN", "epoch"
    ORDER BY \"epoch\";
    """

    print(sql)
    primdb_file = "testdb.db"
    primdb_cnxn = sqlite3.connect(primdb_file)
    cur = primdb_cnxn.cursor()
    cur.execute(sql)
    results = cur.fetchall()
    print(results)

> python .\testsql.py

SELECT "123456789" as ArraySN,
strftime('%Y-%m-%d %H:%M:%S', datetime(tsecs, 'unixepoch')) as "Date   Time",
floor(tsecs/1800) * 1800 as "epoch",
'W' as "R/W", sum(wsize5) as "16k"
FROM statvlun GROUP BY "Array SN", "epoch"
ORDER BY "epoch";


Traceback (most recent call last):
  File ".\testsql.py", line 34, in <module>
    main()
  File ".\testsql.py", line 29, in main
    cur.execute(sql)
sqlite3.OperationalError: no such function: floor