He visto varias dudas sobre la conversión de datos datetime y sus formatos, por eso quisiera compartir este artículo que a mi siempre me viene de mucha ayuda siempre.
Ejecutar los siguientes scripts en Sql Server para demostrar las funciones de conversion y casteo para la transformación de los tipos de datos string y datetime.
-- SQL Server string to date / datetime conversion - datetime string format sql server
-- MSSQL string to datetime conversion - convert char to date - convert varchar to date
-- Subtract 100 from style number (format) for yy instead yyyy (or ccyy with century)
SELECT convert(datetime, 'Oct 23 2012 11:01AM', 100) -- mon dd yyyy hh:mmAM (or PM)
SELECT convert(datetime, 'Oct 23 2012 11:01AM') -- 2012-10-23 11:01:00.000
-- Without century (yy) string date conversion - convert string to datetime function
SELECT convert(datetime, 'Oct 23 12 11:01AM', 0) -- mon dd yy hh:mmAM (or PM)
SELECT convert(datetime, 'Oct 23 12 11:01AM') -- 2012-10-23 11:01:00.000
-- Convert string to datetime sql - convert string to date sql - sql dates format
-- T-SQL convert string to datetime - SQL Server convert string to date
SELECT convert(datetime, '10/23/2016', 101) -- mm/dd/yyyy
SELECT convert(datetime, '2016.10.23', 102) -- yyyy.mm.dd
SELECT convert(datetime, '23/10/2016', 103) -- dd/mm/yyyy
SELECT convert(datetime, '23.10.2016', 104) -- dd.mm.yyyy
SELECT convert(datetime, '23-10-2016', 105) -- dd-mm-yyyy
-- mon types are nondeterministic conversions, dependent on language setting
SELECT convert(datetime, '23 OCT 2016', 106) -- dd mon yyyy
SELECT convert(datetime, 'Oct 23, 2016', 107) -- mon dd, yyyy
-- 2016-10-23 00:00:00.000
SELECT convert(datetime, '20:10:44', 108) -- hh:mm:ss
-- 1900-01-01 20:10:44.000
-- mon dd yyyy hh:mm:ss:mmmAM (or PM) - sql time format - SQL Server datetime format
SELECT convert(datetime, 'Oct 23 2016 11:02:44:013AM', 109)
-- 2016-10-23 11:02:44.013
SELECT convert(datetime, '10-23-2016', 110) -- mm-dd-yyyy
SELECT convert(datetime, '2016/10/23', 111) -- yyyy/mm/dd
-- YYYYMMDD ISO date format works at any language setting - international standard
SELECT convert(datetime, '20161023')
SELECT convert(datetime, '20161023', 112) -- yyyymmdd
-- 2016-10-23 00:00:00.000
SELECT convert(datetime, '23 Oct 2016 11:02:07:577', 113) -- dd mon yyyy hh:mm:ss:mmm
-- 2016-10-23 11:02:07.577
SELECT convert(datetime, '20:10:25:300', 114) -- hh:mm:ss:mmm(24h)
-- 1900-01-01 20:10:25.300
SELECT convert(datetime, '2016-10-23 20:44:11', 120) -- yyyy-mm-dd hh:mm:ss(24h)
-- 2016-10-23 20:44:11.000
SELECT convert(datetime, '2016-10-23 20:44:11.500', 121) -- yyyy-mm-dd hh:mm:ss.mmm
-- 2016-10-23 20:44:11.500
-- Style 126 is ISO 8601 format: international standard - works with any language setting
SELECT convert(datetime, '2008-10-23T18:52:47.513', 126) -- yyyy-mm-ddThh:mm:ss(.mmm)
-- 2008-10-23 18:52:47.513
-- Convert DDMMYYYY format to datetime - sql server to date / datetime
SELECT convert(datetime, STUFF(STUFF('31012016',3,0,'-'),6,0,'-'), 105)
-- 2016-01-31 00:00:00.000
-- SQL Server T-SQL string to datetime conversion without century - some exceptions
-- nondeterministic means language setting dependent such as Mar/Mär/mars/márc
SELECT convert(datetime, 'Oct 23 16 11:02:44AM') -- Default
SELECT convert(datetime, '10/23/16', 1) -- mm/dd/yy U.S.
SELECT convert(datetime, '16.10.23', 2) -- yy.mm.dd ANSI
SELECT convert(datetime, '23/10/16', 3) -- dd/mm/yy UK/FR
SELECT convert(datetime, '23.10.16', 4) -- dd.mm.yy German
SELECT convert(datetime, '23-10-16', 5) -- dd-mm-yy Italian
SELECT convert(datetime, '23 OCT 16', 6) -- dd mon yy non-det.
SELECT convert(datetime, 'Oct 23, 16', 7) -- mon dd, yy non-det.
SELECT convert(datetime, '20:10:44', 8) -- hh:mm:ss
SELECT convert(datetime, 'Oct 23 16 11:02:44:013AM', 9) -- Default with msec
SELECT convert(datetime, '10-23-16', 10) -- mm-dd-yy U.S.
SELECT convert(datetime, '16/10/23', 11) -- yy/mm/dd Japan
SELECT convert(datetime, '161023', 12) -- yymmdd ISO
SELECT convert(datetime, '23 Oct 16 11:02:07:577', 13) -- dd mon yy hh:mm:ss:mmm EU dflt
SELECT convert(datetime, '20:10:25:300', 14) -- hh:mm:ss:mmm(24h)
SELECT convert(datetime, '2016-10-23 20:44:11',20) -- yyyy-mm-dd hh:mm:ss(24h) ODBC can.
SELECT convert(datetime, '2016-10-23 20:44:11.500', 21)-- yyyy-mm-dd hh:mm:ss.mmm ODBC
------------
-- SQL Datetime Data Type: Combine date & time string into datetime - sql hh mm ss
-- String to datetime - mssql datetime - sql convert date - sql concatenate string
DECLARE @DateTimeValue varchar(32), @DateValue char(8), @TimeValue char(6)
SELECT @DateValue = '20120718',
@TimeValue = '211920'
SELECT @DateTimeValue =
convert(varchar, convert(datetime, @DateValue), 111)
+ ' ' + substring(@TimeValue, 1, 2)
+ ':' + substring(@TimeValue, 3, 2)
+ ':' + substring(@TimeValue, 5, 2)
SELECT
DateInput = @DateValue, TimeInput = @TimeValue,
DateTimeOutput = @DateTimeValue;
/*
DateInput TimeInput DateTimeOutput
20120718 211920 2012/07/18 21:19:20 */