数据库函数比较:修订间差异

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第24行: 第24行:
|sysdate - 10
|sysdate - 10
|2023/12/9 10:16:22
|2023/12/9 10:16:22
|-
|默认日期
|default current_timestamp
|default now()
|default sysdate
|2023/11/19 10:22:15
|}
|}


第43行: 第49行:
=== Json ===
=== Json ===
{| class="wikitable"
{| class="wikitable"
|Type
|
|MySQL
|MySQL
|Doris
|Doris
|Clickhouse
|Result
|Result
|-
|-
|Json
|字符串转为Json
|select   j1 -> '$."v1"'
|select cast('{"v1":"10", "v2":"11"}' as json)  
from     (
|select cast('{"v1":"10", "v2":"11"}' as json)  
        select   cast('{"v1":"10", "v2":"11"}' as json)  j1
|Auto
        ) o
|{"v1":"10", "v2":"11"}
<nowiki>;</nowiki>
|
|"10"
|-
|Json
|select   JSON_EXTRACT(cast('{"v1":"10", "v2":"11"}' as json), '$."v1"')
|=
|"10"
|-
|-
|String
|取Json字段值
|select   trim('"10"', '"')
|select j1 ->> '$."v1"'
|=
|select get_json_string(j1, '$.v1')
|select JSONExtractString(j1, 'v1')
|10
|10
|-
|
|
|
|
|}
|}
[[分类:Develop]]
[[分类:DB]]

2023年11月30日 (四) 12:02的最新版本

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

Rand

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

Json

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