数据库函数比较

Date

	MySQL	Clickhouse	Oracle	Result
转字符串	date_format(now(), '%Y%m%d%H%m%S')	toYYYYMMDDhhmmss(now())	to_char(sysdate, 'yyyymmddhh24miss')	20231129103552
日期增	adddate(now(), 10)	date_add(day, 10, now())	sysdate + 10	2023/11/19 10:18:10
日期减	subdate(now(), 10)	date_sub(day, 10, now())	sysdate - 10	2023/12/9 10:16:22

Rand

	MySQL	Clickhouse	Oracle	Result
随机数	cast(rand() * 1000 as int)	trunc(rand()/10000000)	dbms_random.value(0,1000)	121

Json

Type	MySQL	Doris	Result
Json	select   j1 -> '$."v1"' from     (         select   cast('{"v1":"10", "v2":"11"}' as json)  j1         ) o ;		"10"
Json	select   JSON_EXTRACT(cast('{"v1":"10", "v2":"11"}' as json), '$."v1"')	=	"10"
String	select   trim('"10"', '"')	=	10