SQLite与Oracle-计算日期差异-小时数
我想知道是否有人看到了这一点，是否有解决办法，或者我只是做得不对。我试图得到现在和数据库记录中“创建日期”之间的小时差——不是试图得到总小时数，而是去掉总天数后剩下的小时数，这样你就可以输出某物是x天，x小时 初始给定值 让我们使用一个SQLite与Oracle-计算日期差异-小时数,oracle,sqlite,date,date-difference,Oracle,Sqlite,Date,Date Difference,我想知道是否有人看到了这一点，是否有解决办法，或者我只是做得不对。我试图得到现在和数据库记录中“创建日期”之间的小时差——不是试图得到总小时数，而是去掉总天数后剩下的小时数，这样你就可以输出某物是x天，x小时 初始给定值 让我们使用一个SYSDATE，或12/6/2016 6:41 PM的“现在” 假设我有一个Oracle表和一个SQLite表，我们称之为MyTable。在其中，我有一个CREATED_DATE字段，其中日期存储在本地时间： CREATED_DATE ------------ 1
SYSDATE12/6/2016 6:41 PMMyTableCREATED_DATECREATED_DATE
------------
1/20/2015 1:35:17 PM
6/9/2016 3:10:46 PM
DATE从MyTable中选择（SYSDATE-CREATED_DATE）686.211284…180.144976…从MyTable中选择（julianday（'now'）-julianday（创建日期，'utc'））686.212924…180.188283…'utc'julianday（）.211284 x 24 = 5.07 hours
.212924 x 24 = 5.11 hours
.144976 x 24 = 3.479 hours
.188283 x 24 = 4.519 hours
SELECT FLOOR(((SYSDATE - CREATED_DATE)-(FLOOR(SYSDATE - CREATED_DATE)))*24) FROM MyTable
(((julianday('now') - julianday(CREATED_DATE, 'utc')) -
CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER))*24)
就我所知，SQLite的日光更改似乎丢失了，或者确切地说，您需要在保存时指定此更改（因为它是一个字符串，而不是一个真正的日期字段/透明时间戳） 生成日期（如果生成）时，将其设为完整UTC，时区为显式，而非本地隐式： 格式2到10可以可选地后跟时区 形式为“[+-]HH:MM”或仅为“Z”的指示器。日期和时间 函数在内部使用UTC或“zulu”时间，因此“Z”后缀是 不可操作。任何非零的“HH:MM”后缀将从指示的值中减去 计算祖鲁时间的日期和时间。例如，所有 以下时间字符串是等效的：
2013-10-07 08:23:19.120
2013-10-07T08:23:19.120Z
2013-10-07 04:23:19.120-04:00
utcjulianday（'now'）'UTC'（对不起，如果我不明白，我明天再看一次） 实际上你错过了一个重要的信息：你认为哪一个值是正确的？你必须考虑夏时制吗？< /P> 从Oracle开始： 我假设列
CREATED\u DATEDATESYSDATEDATESELECT
TO_DATE('2016-12-06 06:00:00','YYYY-MM-DD HH24:MI:SS')
- TO_DATE('2016-06-09 06:00:00','YYYY-MM-DD HH24:MI:SS')
FROM dual;
如果你必须考虑夏令时，你必须使用数据类型<代码>时间戳，带时区< /代码>（或<代码>本地本地时区时间戳），请参见这个例子：
SELECT
TO_TIMESTAMP_TZ('2016-12-06 06:00:00 Europe/Zurich','YYYY-MM-DD HH24:MI:SS TZR')
- TO_TIMESTAMP_TZ('2016-06-09 06:00:00 Europe/Zurich','YYYY-MM-DD HH24:MI:SS TZR')
FROM dual;
+180 01:00:00.000000时间戳日期楼层 SELECT
EXTRACT(HOUR FROM SYSTIMESTAMP - CREATED_DATE) AS diff_hours
FROM MyTable;
LOCALTIMESTAMPTIMESTAMPSYSTIMESTAMPCURRENT_TIMESTAMP现在考虑<强> SQLite < /强>：
更新create table t (CREATED_DATE DATE);
insert into t values (datetime('2015-06-01 00:00:00'));
insert into t values (datetime('2015-12-01 00:00:00'));
insert into t values (datetime('2016-06-01 00:00:00'));
insert into t values (datetime('2016-12-01 00:00:00'));
select datetime('now', 'localtime') as now,
created_date,
julianday('now') - julianday(CREATED_DATE, 'utc') as wrong_delta_days,
strftime('%j %H:%M:%S', datetime('0000-01-01T00:00:00', '+'||(julianday('now') - julianday(CREATED_DATE, 'utc'))||' day', '-1 day')) as wrong_delta,
strftime('%j %H:%M:%S', datetime('0000-01-01T00:00:00', '+'||(julianday('now', 'localtime') - julianday(CREATED_DATE))||' day', '-1 day')) as delta_1,
strftime('%j %H:%M:%S',
datetime('now', 'localtime',
'-'||strftime('%Y', CREATED_DATE)||' year',
'-'||strftime('%j', CREATED_DATE)||' day',
'-'||strftime('%H', CREATED_DATE)||' hour',
'-'||strftime('%M', CREATED_DATE)||' minute',
'-'||strftime('%S', CREATED_DATE)||' second'
)) as delta_2,
strftime('%j %H:%M:%S', datetime('0000-01-01T00:00:00', '+'||(julianday(datetime('now', 'localtime')||'Z') - julianday(CREATED_DATE||'Z'))||' day', '-1 day')) as delta_3
from t;
now | CREATED_DATE | wrong_delta_days | wrong_delta | delta_1 | delta_2 | delta_3
2016-12-08 08:34:08 | 2015-06-01 00:00:00 | 556.398711088113 | 190 09:34:08 | 190 08:34:08 | 190 08:34:08 | 190 08:34:08
2016-12-08 08:34:08 | 2015-12-01 00:00:00 | 373.357044421136 | 007 08:34:08 | 007 08:34:08 | 007 08:34:08 | 007 08:34:08
2016-12-08 08:34:08 | 2016-06-01 00:00:00 | 190.398711088113 | 190 09:34:08 | 190 08:34:08 | 190 08:34:08 | 190 08:34:08
2016-12-08 08:34:08 | 2016-12-01 00:00:00 | 7.35704442113638 | 007 08:34:08 | 007 08:34:08 | 007 08:34:08 | 007 08:34:08
private void BindTable()
{
DataTable dt = ADOClass.adoDataTable;
if (!Oracle_DAL.ConnTest()) // if no Oracle connection, SQLite is running and it needs DST correction
{
int oldHours = 0;
int newHours = 0;
int oldDays = 0;
int newDays = 0;
string ageCell = String.Empty;
string hoursString = String.Empty;
string daysString = String.Empty;
string crDate = String.Empty;
if (dt != null && dt.Rows != null)
{
if (dt.Rows.Count > 0)
{
foreach (DataRow dr in dt.Rows)
{
crDate = dr["CREATED_DATE"] != null ? dr["CREATED_DATE"].ToString() : String.Empty;
if (!String.IsNullOrEmpty(crDate))
{
DateTime createdDate = DateTime.Parse(crDate);
if (createdDate.IsDaylightSavingTime())
{
ageCell = dr["AGE"] != null ? dr["AGE"].ToString() : String.Empty;
if (!String.IsNullOrEmpty(ageCell))
{
hoursString = ageCell.Split(',')[3];
hoursString = hoursString.TrimStart(' ');
oldHours = int.Parse(hoursString.Split(' ')[0]);
if (oldHours == 0)
{
newHours = 23;
daysString = ageCell.Split(',')[2];
daysString = daysString.TrimStart(' ');
oldDays = int.Parse(daysString.Split(' ')[0]);
oldDays--;
newDays = oldDays;
ageCell = ageCell.Replace(daysString, newDays.ToString() + " days");
dr["AGE"] = ageCell;
}
else
{
oldHours--;
newHours = oldHours;
}
dr["AGE"] = ageCell.Replace(hoursString, newHours.ToString() + " hours");
}
}
}
}
}
}
}
lstData.DataContext = dt; // binds to my ListView's grid
}
SELECT CREATED_DATE, (SYSDATE - CREATED_DATE) AS TOTALDAYS,
FLOOR(ABS(MONTHS_BETWEEN(CREATED_DATE, SYSDATE)) / 12) || ' years, '
|| (FLOOR(ABS(MONTHS_BETWEEN(CREATED_DATE, SYSDATE))) -
(FLOOR(ABS(MONTHS_BETWEEN(CREATED_DATE, SYSDATE)) / 12)) * 12) || ' months, '
-- we take total days - years(as days) - months(as days) to get remaining days
|| FLOOR((SYSDATE - CREATED_DATE) - -- total days
(FLOOR((SYSDATE - CREATED_DATE)/365)*12)*(365/12) - -- years, as days
-- this is total months - years (as months), to get number of months,
-- then multiplied by 30.416667 to get months as days (and remove it from total days)
FLOOR(FLOOR(((SYSDATE - CREATED_DATE)/365)*12 - (FLOOR((SYSDATE - CREATED_DATE)/365)*12)) * (365/12)))
|| ' days, '
-- Here, we can just get the remainder decimal from total days minus
-- floored total days and multiply by 24
|| FLOOR(
((SYSDATE - CREATED_DATE)-(FLOOR(SYSDATE - CREATED_DATE)))*24
)
|| ' hours, '
-- Minutes just use the unfloored hours equation minus floored hours,
-- then multiply by 60
|| ROUND(
(
(
((SYSDATE - CREATED_DATE)-(FLOOR(SYSDATE - CREATED_DATE)))*24
) -
FLOOR((((SYSDATE - CREATED_DATE)-(FLOOR(SYSDATE - CREATED_DATE)))*24))
)*60
)
|| ' minutes'
AS AGE FROM MyTable`
private static readonly string mainqueryCommandTextSQLite = "SELECT " +
"CREATED_DATE, " +
" (julianday('now') - julianday(CREATED_DATE, 'utc')) AS TOTALDAYS, " +
// " (((julianday('now') - julianday(CREATED_DATE))/365)*12) || ' total months, ' || " +
// " ((CAST ((julianday('now') - julianday(CREATED_DATE))/365 AS INTEGER))*12) || ' years as months, ' || " +
// Provide years, months
" CAST ((julianday('now') - julianday(CREATED_DATE, 'utc'))/365 AS INTEGER) || ' years, ' || " +
" CAST (((((julianday('now') - julianday(CREATED_DATE, 'utc'))/365)*12) - (CAST ((julianday('now') - julianday(CREATED_DATE, 'utc'))/365 AS INTEGER)*12)) AS INTEGER) || ' months, ' " +
// Provide days
"|| ((CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER) - " + // total number of days
" (CAST ((julianday('now') - julianday(CREATED_DATE, 'utc'))/365 AS INTEGER)*365) ) -" + // years in days
" CAST((30.41667 * ((CAST ((((julianday('now') - julianday(CREATED_DATE, 'utc'))/365)*12) AS INTEGER)) - ((CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) / 365 AS INTEGER)) * 12))) AS INTEGER)) " + // days of remaining months using total months - months from # of floored years * (365/12)
" || ' days, ' " +
// BUG: These next two do not get accurate hours during DST months (March - Nov)
// This gives hours
"|| CAST ((((julianday('now') - julianday(CREATED_DATE, 'utc')) - " +
" CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER))*24) AS INTEGER) " +
// This gives hours.minutes
//"|| (((julianday('now') - julianday(CREATED_DATE, 'utc')) - CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER))*24) " +
// This gives days.hours, but taking the decimal and multiplying by 24 to get actual hours
// gives an incorrect result
//"|| ((" +
// "(0.0 + strftime('%S', 'now', 'localtime') " +
// "+ 60*strftime('%M', 'now', 'localtime') " +
// "+ 24*60*strftime('%H', 'now', 'localtime') " +
// "+ 24*60*60*strftime('%j', 'now', 'localtime')) - " +
// "(strftime('%S', CREATED_DATE) " +
// "+ 60*strftime('%M', CREATED_DATE) " +
// "+ 24*60*strftime('%H', CREATED_DATE) " +
// "+ 24*60*60*strftime('%j', CREATED_DATE)) " +
// ")/60/60/24) " +
"|| ' hours, ' " +
// Provide minutes
"|| CAST (ROUND(((((julianday('now') - julianday(CREATED_DATE, 'utc')) - CAST ((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER))*24) - " +
"(CAST((((julianday('now') - julianday(CREATED_DATE, 'utc')) - CAST((julianday('now') - julianday(CREATED_DATE, 'utc')) AS INTEGER)) * 24) AS INTEGER)))*60) AS INTEGER)" +
"|| ' minutes' " +
" AS AGE FROM MyTable";