如何在 postgres 中创建 ISO-8601 公历日期 table
how to create ISO-8601 gregorian date table in postgres
我想在 postgres 数据库中创建一个日期 table。
示例数据预计如下所示：
date key = 00001
calendar_date= 1/1/2015
week_num= 1
month_num= 1
month_name= Jan
quarter_num= 1
calendar_year= 2015
iso_dayofweek= 4
dayofweek_name= Thursday
是否有函数或 SQL 可以帮助我创建日期公历 ISO-8601 table？
如果可能的话，我希望自动生成它。在这方面的任何帮助将不胜感激。
看下面的例子
SELECT mydate calendar_date
,EXTRACT(WEEK FROM mydate) week_num
,EXTRACT(month FROM mydate) month_num
,to_char(mydate,'Mon') month_name
,EXTRACT(Quarter FROM mydate) quarter_num
,EXTRACT(year FROM mydate) calendar_year
,EXTRACT(DOW FROM mydate) iso_dayofweek
,to_char(mydate, 'day') dayofweek_name
FROM (
SELECT now()::DATE mydate
) t
结果：
calendar_date week_num month_num month_name quarter_num calendar_year iso_dayofweek dayofweek_name
------------- -------- --------- ---------- ----------- ------------- ------------- --------------
2015/04/24 17 4 Apr 2 2015 5 friday
您可以使用 generate_series() 获取一年中的所有日期，例如：2015
select generate_series(0,364) + date'1/1/2015'
这将从 1/1/2015 - 31/12/2015 生成日期，并在给定示例
中使用此 select 而不是 SELECT now()::DATE
如果要为 2015 年创建 table，则可以使用以下查询
CREATE TABLE mycal_2015 AS
SELECT row_number() OVER () date_key
,mydate calendar_date
,EXTRACT(WEEK FROM mydate) week_num
,EXTRACT(month FROM mydate) month_num
,to_char(mydate,'Mon') month_name
,EXTRACT(Quarter FROM mydate) quarter_num
,EXTRACT(year FROM mydate) calendar_year
,EXTRACT(DOW FROM mydate) iso_dayofweek
,to_char(mydate, 'day') dayofweek_name
FROM (
SELECT generate_series(0, 364) + DATE '1/1/2015' mydate
) t
并且 table 看起来像 select * from mycal_2015
date_key calendar_date week_num month_num month_name quarter_num calendar_year iso_dayofweek dayofweek_name
-------- ------------- -------- --------- ---------- ----------- ------------- ------------- --------------
1 2015/01/01 1 1 Jan 1 2015 4 thursday
2 2015/01/02 1 1 Jan 1 2015 5 friday
3 2015/01/03 1 1 Jan 1 2015 6 saturday
4 2015/01/04 1 1 Jan 1 2015 0 sunday
5 2015/01/05 2 1 Jan 1 2015 1 monday
6 2015/01/06 2 1 Jan 1 2015 2 tuesday
...
.
.
.
364 2015/12/30 53 12 Dec 4 2015 3 wednesday
365 2015/12/31 53 12 Dec 4 2015 4 thursday
POSTGRESQL：提取函数
PostgreSQL 提取函数从日期中提取部分
语法：extract( unit from date )
date is a date, timestamp, time, or interval value from which the date
part is to be extracted.
unit is the unit type of the interval such as day, month, minute,
hour, and so on
可以是以下之一：
unit description
--------------- -----------------------------------------------------------------------------------------------------------------------------
century Uses the Gregorian calendar where the first century starts at '0001-01-01 00:00:00 AD'
day Day of the month (1 to 31)
decade Year divided by 10
dow Day of the week (0=Sunday, 1=Monday, 2=Tuesday, ... 6=Saturday)
doy Day of the year (1=first day of year, 365/366=last day of the year, depending if it is a leap year)
epoch Number of seconds since '1970-01-01 00:00:00 UTC', if date value. Number of seconds in an interval, if interval value
hour Hour (0 to 23)
isodow Day of the week (1=Monday, 2=Tuesday, 3=Wednesday, ... 7=Sunday)
isoyear ISO 8601 year value (where the year begins on the Monday of the week that contains January 4th)
microseconds Seconds (and fractional seconds) multiplied by 1,000,000
millennium Millennium value
milliseconds Seconds (and fractional seconds) multiplied by 1,000
minute Minute (0 to 59)
month Number for the month (1 to 12), if date value. Number of months (0 to 11), if interval value
quarter Quarter (1 to 4)
second Seconds (and fractional seconds)
timezone Time zone offset from UTC, expressed in seconds
timezone_hour Hour portion of the time zone offset from UTC
timezone_minute Minute portion of the time zone offset from UTC
week Number of the week of the year based on ISO 8601 (where the year begins on the Monday of the week that contains January 4th)
year Year as 4-digits
注：Extract功能适用于PostgreSQL 8.4及以上版本
我想在 postgres 数据库中创建一个日期 table。 示例数据预计如下所示：
date key = 00001
calendar_date= 1/1/2015
week_num= 1
month_num= 1
month_name= Jan
quarter_num= 1
calendar_year= 2015
iso_dayofweek= 4
dayofweek_name= Thursday
是否有函数或 SQL 可以帮助我创建日期公历 ISO-8601 table？
如果可能的话，我希望自动生成它。在这方面的任何帮助将不胜感激。
看下面的例子
SELECT mydate calendar_date
,EXTRACT(WEEK FROM mydate) week_num
,EXTRACT(month FROM mydate) month_num
,to_char(mydate,'Mon') month_name
,EXTRACT(Quarter FROM mydate) quarter_num
,EXTRACT(year FROM mydate) calendar_year
,EXTRACT(DOW FROM mydate) iso_dayofweek
,to_char(mydate, 'day') dayofweek_name
FROM (
SELECT now()::DATE mydate
) t
结果：
calendar_date week_num month_num month_name quarter_num calendar_year iso_dayofweek dayofweek_name
------------- -------- --------- ---------- ----------- ------------- ------------- --------------
2015/04/24 17 4 Apr 2 2015 5 friday
您可以使用 generate_series() 获取一年中的所有日期，例如：2015
select generate_series(0,364) + date'1/1/2015'
这将从 1/1/2015 - 31/12/2015 生成日期，并在给定示例
SELECT now()::DATE
如果要为 2015 年创建 table，则可以使用以下查询
CREATE TABLE mycal_2015 AS
SELECT row_number() OVER () date_key
,mydate calendar_date
,EXTRACT(WEEK FROM mydate) week_num
,EXTRACT(month FROM mydate) month_num
,to_char(mydate,'Mon') month_name
,EXTRACT(Quarter FROM mydate) quarter_num
,EXTRACT(year FROM mydate) calendar_year
,EXTRACT(DOW FROM mydate) iso_dayofweek
,to_char(mydate, 'day') dayofweek_name
FROM (
SELECT generate_series(0, 364) + DATE '1/1/2015' mydate
) t
并且 table 看起来像 select * from mycal_2015
date_key calendar_date week_num month_num month_name quarter_num calendar_year iso_dayofweek dayofweek_name
-------- ------------- -------- --------- ---------- ----------- ------------- ------------- --------------
1 2015/01/01 1 1 Jan 1 2015 4 thursday
2 2015/01/02 1 1 Jan 1 2015 5 friday
3 2015/01/03 1 1 Jan 1 2015 6 saturday
4 2015/01/04 1 1 Jan 1 2015 0 sunday
5 2015/01/05 2 1 Jan 1 2015 1 monday
6 2015/01/06 2 1 Jan 1 2015 2 tuesday
...
.
.
.
364 2015/12/30 53 12 Dec 4 2015 3 wednesday
365 2015/12/31 53 12 Dec 4 2015 4 thursday
POSTGRESQL：提取函数
PostgreSQL 提取函数从日期中提取部分
语法：extract( unit from date )
date is a date, timestamp, time, or interval value from which the date part is to be extracted.
unit is the unit type of the interval such as day, month, minute, hour, and so on
可以是以下之一：
unit description
--------------- -----------------------------------------------------------------------------------------------------------------------------
century Uses the Gregorian calendar where the first century starts at '0001-01-01 00:00:00 AD'
day Day of the month (1 to 31)
decade Year divided by 10
dow Day of the week (0=Sunday, 1=Monday, 2=Tuesday, ... 6=Saturday)
doy Day of the year (1=first day of year, 365/366=last day of the year, depending if it is a leap year)
epoch Number of seconds since '1970-01-01 00:00:00 UTC', if date value. Number of seconds in an interval, if interval value
hour Hour (0 to 23)
isodow Day of the week (1=Monday, 2=Tuesday, 3=Wednesday, ... 7=Sunday)
isoyear ISO 8601 year value (where the year begins on the Monday of the week that contains January 4th)
microseconds Seconds (and fractional seconds) multiplied by 1,000,000
millennium Millennium value
milliseconds Seconds (and fractional seconds) multiplied by 1,000
minute Minute (0 to 59)
month Number for the month (1 to 12), if date value. Number of months (0 to 11), if interval value
quarter Quarter (1 to 4)
second Seconds (and fractional seconds)
timezone Time zone offset from UTC, expressed in seconds
timezone_hour Hour portion of the time zone offset from UTC
timezone_minute Minute portion of the time zone offset from UTC
week Number of the week of the year based on ISO 8601 (where the year begins on the Monday of the week that contains January 4th)
year Year as 4-digits
注：Extract功能适用于PostgreSQL 8.4及以上版本