常用SQL：修订间差异
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== MySQL == | ==== 空值转为 0 ==== | ||
* MySQL | |||
case when (col > '') then col else 0 end | |||
==== 固定长度数字 ==== | |||
* MySQL | |||
substr(concat('00000', floor(rand() * 1000000)), -6) | |||
==== 近一百天内时间 ==== | |||
* Doris | |||
date_add(now(), - rand() * 100) | |||
* MySQL | |||
date_add(now(), interval - RAND() * 100 day) | |||
==== 生成连续数字 ==== | ==== 生成连续数字 ==== | ||
* MySQL | * MySQL | ||
| 第48行： | 第61行： | ||
) | ) | ||
select 1 from t1, t2, t3 | select 1 from t1, t2, t3 | ||
[[分类:Develop]] | [[分类:Develop]] | ||
[[分类:DB]] | [[分类:DB]] | ||
2024年1月22日 (一) 13:13的最新版本
空值转为 0
- MySQL
case when (col > ) then col else 0 end
固定长度数字
- MySQL
substr(concat('00000', floor(rand() * 1000000)), -6)
近一百天内时间
- Doris
date_add(now(), - rand() * 100)
- MySQL
date_add(now(), interval - RAND() * 100 day)
生成连续数字
- MySQL
with recursive seq(no) as(
select 1 no
union all
select no+1 no
from seq
where no < 100
)
select no
from seq
- MySQL, Doris, Oracle
with t1 as (
with a as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
),
b as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
)
select 1 from a, b
),
t2 as (
with a as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
),
b as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
)
select 1 from a, b
),
t3 as (
with a as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
),
b as (
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
)
select 1 from a, b
limit 100
)
select 1 from t1, t2, t3