(012) Daily SQL Learning: To_char (Date,format)

Sysdate	2009-6-16 15:25:10
TRUNC (Sysdate)	2009-6-16
To_char (sysdate, ' YYYYMMDD ')	20090616	to Japan
To_char (sysdate, ' YYYYMMDD HH24:MI:SS ')	20090616 15:25:10	to seconds
To_char (Systimestamp, ' YYYYMMDD HH24:MI:SS. FF3 ')	20090616 15:25:10.848	to milliseconds
To_char (sysdate, ' AD ')	Ad
To_char (sysdate, ' AM ')	Afternoon
To_char (sysdate, ' BC ')	Ad
To_char (sysdate, ' CC ')	21st
To_char (sysdate, ' D ')	3	The day of the foreigner
To_char (sysdate, ' Day ')	Tuesday	Day of the Week
To_char (sysdate, ' DD ')	16
To_char (sysdate, ' DDD ')	167
To_char (sysdate, ' DL ')	June 16, 2009 Tuesday
To_char (sysdate, ' DS ')	2009-06-16
To_char (sysdate, ' DY ')	Tuesday
To_char (Systimestamp, ' SS. FF3 ')	10.848	Milliseconds
To_char (sysdate, ' FM ')
To_char (sysdate, ' FX ')
To_char (sysdate, ' HH ')	03
To_char (sysdate, ' HH24 ')	15
To_char (sysdate, ' IW ')	25	The first few weeks
To_char (sysdate, ' iyy ')	009
To_char (sysdate, ' IY ')	09
To_char (sysdate, ' J ')	2454999
To_char (sysdate, ' MI ')	25
To_char (sysdate, ' MM ')	06
To_char (sysdate, ' MON ')	June
To_char (sysdate, ' MONTH ')	June
To_char (Systimestamp, ' PM ')	Afternoon
To_char (sysdate, ' Q ')	2	First quarter
To_char (sysdate, ' RM ')	VI
To_char (sysdate, ' RR ')	09
To_char (sysdate, ' RRRR ')	2009
To_char (sysdate, ' SS ')	10
To_char (sysdate, ' sssss ')	55510
To_char (sysdate, ' TS ')	3:25:10
To_char (sysdate, ' WW ')	24
To_char (Systimestamp, ' W ')	3
To_char (Sysdate, ' year ')	Thousand NINE
To_char (sysdate, ' YYYY ')	2009
To_char (Systimestamp, ' YYY ')	009
To_char (Systimestamp, ' YY ')	09

Transfer from: http://blog.csdn.net/suncrafted/article/details/4273528

SelectTrunc (Sysdate,'yy') fromDual;--first day of the yearSelectTrunc (Sysdate,'mm') fromDual--first day of the monthSelectTrunc (Sysdate,' Day')+1  fromDual--first day of the week

--How many weeks are there in a year? withX0 as (SelectTo_date ('2018-01-01','YYYY-MM-DD') asEarly fromdual), X1 as (SelectAt the beginning of the year, Add_months (early A) asAt the beginning of next year fromx0), X2 as (SelectEarly next year, early next year-Early asDays fromx1), X3 as (SelectEarly+ Level-1  asDate fromX2 Connect by  Level <=days), X4 as (SelectDate, To_char (date,' Day') asWeek fromX3)SELECTWeekCount(*) fromX4Group  byWeek

(012) Daily SQL Learning: To_char (Date,format)