convert datetime in varchar sql server code example

Example 1: sql server convert string to date

Cast( '2011-07-07' as date ) as convertedDate

Example 2: sql convert date

Example 
SELECT CONVERT(varchar, '2017-08-25', 101);

CONVERT(data_type(length), expression, style)

Converting datetime to character:
Without century	With century	Input/Output	Standard
0	100	mon dd yyyy hh:miAM/PM	Default
1	101	mm/dd/yyyy	US
2	102	 yyyy.mm.dd	ANSI
3	103	 dd/mm/yyyy	British/French
4	104	dd.mm.yyyy	German
5	105	 dd-mm-yyyy	Italian
6	106	dd mon yyyy	-
7	107	Mon dd, yyyy	-
8	108	hh:mm:ss	-
9	109	mon dd yyyy hh:mi:ss:mmmAM (or PM)	Default + millisec
10	110	mm-dd-yyyy	USA
11	111	 yyyy/mm/dd	Japan
12	112	 yyyymmdd	ISO
13	113	dd mon yyyy hh:mi:ss:mmm	Europe (24 hour clock)>
14	114	hh:mi:ss:mmm	24 hour clock
20	120	yyyy-mm-dd hh:mi:ss	ODBC canonical (24 hour clock)
21	121	yyyy-mm-dd hh:mi:ss.mmm	ODBC canonical (24 hour clock)
 	126	yyyy-mm-ddThh:mi:ss.mmm	ISO8601
 	127	yyyy-mm-ddThh:mi:ss.mmmZ	ISO8601 (with time zone Z)
 	130	dd mon yyyy hh:mi:ss:mmmAM	Hijiri
 	131	dd/mm/yy hh:mi:ss:mmmAM	Hijiri