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
|-
|默认日期
|default current_timestamp
|default now()
|default sysdate
|2023/11/19 10:22:15
|}

=== 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"
|
|MySQL
|Doris
|Clickhouse
|Result
|-
|字符串转为Json
|select cast('{"v1":"10", "v2":"11"}' as json) 
|select cast('{"v1":"10", "v2":"11"}' as json) 
|Auto
|{"v1":"10", "v2":"11"}
|-
|取Json字段值
|select j1 ->> '$."v1"'
|select get_json_string(j1, '$.v1')
|select JSONExtractString(j1, 'v1')
|10
|}
[[分类:Develop]]
[[分类:DB]]