查看“数据库函数比较”的源代码

=== Date ===
{| class="wikitable"
|
|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 ===
{| class="wikitable"
|
|MySQL
|Clickhouse
|Oracle
|Result
|-
|随机数
|cast(rand() * 1000 as int)
|trunc(rand()/10000000)
|dbms_random.value(0,1000)
|121
|}

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