Question

问题

我正在尝试使用WHERE部分中的日期时间在Python中执行sqlite3查询。

placementDate是datetime对象，我的代码如下。出于某种原因，查询返回今天放置的项目，而不是最后一小时的投注。可能有什么不对？

    sql = r"""SELECT count(*) FROM bet WHERE placedDate>?"""
    td = timedelta( minutes=60 )
    dt = datetime.utcnow()-td
    with closing( conn.cursor() ) as cur:
        cur.execute( sql, ( dt, ) )
        print cur.fetchone()[0]

我也试过

sql = r"""SELECT count(*) FROM bet WHERE placedDate>datetime(?)"""

示例placementDate是

 'placedDate': u'2015-02-06T01:20:37.000Z',

表格定义

使用

    meta = conn.execute("PRAGMA table_info('bet')")
    print( 'bet table info:')
    for r in meta:
        print r

我得到了

(0, u'id', u'INTEGER', 0, None, 1)
(1, u'marketId', u'varchar', 0, None, 0)
(2, u'sizeMatched', u'decimal(10,2)', 0, None, 0)
(3, u'orderType', u'varchar', 0, None, 0)
(4, u'selectionId', u'int', 0, None, 0)
(5, u'price', u'decimal(5,2)', 0, None, 0)
(6, u'persistenceType', u'varchar', 0, None, 0)
(7, u'size', u'decimal(10,2)', 0, None, 0)
(8, u'placedDate', u'datetime', 0, None, 0)
(9, u'averagePriceMatched', u'decimal(10,2)', 0, None, 0)
(10, u'side', u'varchar', 0, None, 0)
(11, u'description', u'varchar', 0, None, 0)

Answer 1

这对我有用：

 import sqlite3
 from datetime import datetime, timedelta

 conn = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES)


 c = conn.cursor()

 c.execute("""
 CREATE TABLE test (
    foo varchar,
    ts datetime
 );""")

 rowcount = c.execute("SELECT COUNT(*) FROM test").fetchone()[0]
 assert 0 == rowcount, rowcount

 dt = timedelta(minutes=5)

 now = datetime.now()

 then = now

 for i in xrange(100):
     then -= dt
     c.execute("INSERT INTO test VALUES(?, ?)", (str(i), then))

 rowcount = c.execute("SELECT COUNT(*) FROM test").fetchone()[0]
 assert 100 == rowcount, rowcount


 hour_ago = now - timedelta(minutes=60)
 rowcount = c.execute(
     "SELECT COUNT(*) FROM test WHERE ts >= ?",
     (hour_ago,) ).fetchone()[0]
 assert 12 == rowcount, rowcount

如果它适合您，我怀疑数据与您的期望不同。

sqlite3，选择日期时间

1 个答案: