sqlite3日期數據類型

 

1、sqlite3日期數據類型，默認用datetime解析（根據stackflow）

使用時注意三點：

　　1. 建立表時，字段 DT 的類型爲 date

　　2. 插入數據時，DT字段直接爲 str 類型

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

import sqlite3
import datetime

'''sqlite3日期數據類型'''

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：顯式使用 datetime 類型
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 類型
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)

 

2、另外一種方式使用時間類型數據（根據官網文檔）

import sqlite3
import datetime


# 適配器
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()

# 轉換器
def convert_date(string):
    return datetime.datetime.strptime(string.decode(), '%Y/%m/%d')

# 註冊適配器
sqlite3.register_adapter(datetime.datetime, adapt_date)

# 註冊轉換器
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)

# ==============================================================

# 顯示日期等於2016/1/3的記錄
t = ('2016/1/3',)
c.execute('SELECT * FROM marksix WHERE dt = ?', t)
print(c.fetchone())



# 貌似不支持between運算，不知緣由！
for row in c.execute('SELECT * FROM marksix WHERE dt BETWEEN ? AND ?;', ('2016/1/3', '2016/1/11')):
    print(row)

 

3、還有一種日期時間類型：timestamp(時間戳)

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類型
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 類型
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)