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  • sqlite3日期数据类型

    一、sqlite3日期数据类型,默认用datetime解析(根据stackflow

    使用时注意三点:

      1. 创建表时,字段 DT 的类型为 date

      2. 插入数据时,DT字段直接为 str 类型

      3. DT字段的str ,年月日必须为 xxxx-xx-xx 格式,如 2016-01-01,不能是 2016-1-1

    import sqlite3
    import datetime
    
    '''sqlite3日期数据类型'''
    con = sqlite3.connect(":memory:") c = con.cursor() # Create table c.execute('''CREATE TABLE marksix (DT date, Period text, P1 int, P2 int, P3 int, P4 int, P5 int, P6 int, T7 int)''') # Larger example that inserts many records at a time purchases = [('2016-01-01', '2016001', 2, 36, 23, 43, 12, 25, 29), ('2016-01-03', '2016002', 34, 35, 17, 49, 24, 30, 16), ('2016-01-05', '2016003', 1, 35, 12, 49, 49, 26, 34), ('2016-01-08', '2016004', 6, 35, 10, 40, 4, 23, 2), ('2016-01-10', '2016005', 14, 35, 27, 40, 4, 12, 45), ('2016-01-12', '2016006', 33, 10, 13, 21, 27, 22, 17), ('2016-01-15', '2016007', 20, 35, 17, 49, 5, 29, 28), ] c.executemany('INSERT INTO marksix (DT,Period,P1,P2,P3,P4,P5,P6,T7) VALUES (?,?,?,?,?,?,?,?,?)', purchases)
    for row in c.execute('SELECT * FROM marksix'): print(row)
    # ==============================================================

    # 方式一:显式使用 datetime 类型 t = datetime.datetime.strptime('2016-1-5', '%Y-%m-%d') dt = (datetime.date(t.year, t.month, t.day), ) for row in c.execute('SELECT * FROM marksix WHERE DT = ?', dt): print(row) # 方式二:直接使用 str 类型 dt = ('2016-01-05', ) for row in c.execute('SELECT * FROM marksix WHERE DT = ?', dt): print(row)


    #for row in c.execute('SELECT * FROM marksix WHERE dt BETWEEN :begin AND :end;', {"begin": '2016-01-03', "end": '2016-01-11'}): for row in c.execute('SELECT * FROM marksix WHERE dt BETWEEN ? AND ?;', ('2016-01-03', '2016-01-11')): print(row)

    二、另一种方式使用时间类型数据(根据官网文档

    import sqlite3
    import datetime
    
    
    # 适配器
    def adapt_date(date):
        return datetime.datetime.strftime('%Y/%m/%d', date)
        #return date.strftime('%Y/%m/%d').encode('ascii')
        #return date.strftime('%Y/%m/%d').encode()
    
    # 转换器
    def convert_date(string):
        return datetime.datetime.strptime(string.decode(), '%Y/%m/%d')
    
    # 注册适配器
    sqlite3.register_adapter(datetime.datetime, adapt_date)
    
    # 注册转换器
    sqlite3.register_converter("date", convert_date)
    
    
    
    
    # 注意:detect_types=sqlite3.PARSE_DECLTYPES
    con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES)
    c = con.cursor()
    
    
    # Create table
    c.execute('''CREATE TABLE marksix
                (dt date, period text, p1 int, p2 int, p3 int, p4 int, p5 int, p6 int, t7 int)''')
    
    
    # Larger example that inserts many records at a time
    purchases = [('2016/1/1', '2016001', 2, 36, 23, 43, 12, 25, 29),
                 ('2016/1/3', '2016002', 34, 35, 17, 49, 24, 30, 16),
                 ('2016/1/5', '2016003', 1, 35, 12, 49, 49, 26, 34),
                 ('2016/1/8', '2016004', 6, 35, 10, 40, 4, 23, 2),
                 ('2016/1/10', '2016005', 14, 35, 27, 40, 4, 12, 45),
                 ('2016/1/12', '2016006', 33, 10, 13, 21, 27, 22, 17),
                 ('2016/1/15', '2016007', 20, 35, 17, 49, 5, 29, 28),
                ]
    c.executemany('INSERT INTO marksix VALUES (?,?,?,?,?,?,?,?,?)', purchases)
    
    # Save (commit) the changes
    con.commit()
    
    for row in c.execute('SELECT * FROM marksix'):
        print(row)
    
    # ==============================================================
    
    # 显示日期等于2016/1/3的记录
    t = ('2016/1/3',)
    c.execute('SELECT * FROM marksix WHERE dt = ?', t)
    print(c.fetchone())
    
    
    
    # 貌似不支持between运算,不知原因!
    for row in c.execute('SELECT * FROM marksix WHERE dt BETWEEN ? AND ?;', ('2016/1/3', '2016/1/11')):
        print(row)

    三、还有一种日期时间类型:timestamp(时间戳)

    import datetime
    
    
    # Converting SQLite values to custom Python types
    # Default adapters and converters for datetime and timestamp
    con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES)
    cur = con.cursor()
    
    cur.execute('''create table test(
                                    d date, 
                                    ts timestamp
                                    )''')
    
    # 插入datetime类型
    today = datetime.date.today()
    now = datetime.datetime.now()
    day1 = datetime.timedelta(days=1)
    data = [(today-day1, now-day1),
            (today, now),
            (today+day1, now+day1)]
    cur.executemany("insert into test(d, ts) values (?, ?)", data)
    
    # 插入 str 类型
    data = [('2016-01-22', '2016-01-22 08:45:50'),
            ('2016-02-22', '2016-02-22 08:45:50'),
            ('2016-03-22', '2016-03-22 08:45:50')]
    cur.executemany("insert into test(d, ts) values (?, ?)", data)
            
    
    for row in cur.execute("select * from test"):
        print(row)
    
    #=================================================================
    
    #begin = datetime.date(2016, 2, 22)
    #end = datetime.date(2016, 2, 23)
    begin = '2016-02-22'
    end = '2016-02-23'
    for row in cur.execute("select * from test where d BETWEEN ? AND ?", (begin, end)):
        print(row)
    
    
    begin = datetime.datetime(2016, 2, 22, 8, 45, 50, 0)
    end = datetime.datetime(2016, 2, 23, 20, 10, 47, 12345)
    #begin = '2016-02-22 08:45:50'
    #end = '2016-02-23 20:10:47'
    for row in cur.execute("select * from test where ts BETWEEN ? AND ?", (begin, end)):
        print(row)
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  • 原文地址:https://www.cnblogs.com/hhh5460/p/5205982.html
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