MySQL不常用語句

1 指定資料排前面

group by nutr_scheme.id order by nutr_scheme.id not in (select scheme_id from nutr_user_default_scheme where user_id = 10036 and is_delete = 0), drink_count desc, nutr_scheme.id asc

2 多行查詢結果合併一行(適用於一對多)

select

group_concat(name) as all_name,
`name`
from
base_basedata
group by
pid

3 distinct用於去掉count重複值

count(distinct id) as `count`

4 查詢兩分鐘以內資料

create_time >= unix_timestamp(now()-interval 120 second)

5 時間戳(10位)轉時間

from_unixtime(time_stamp, '%y-%m-%d %h:%i:%s')

6 一對多查詢數量

select `user`.id

, `user`.`name`
, user_score.count
from `user`
left join (select user_id
, count(*) count
from user_score
group by user_id) as user_score on user_score.user_id = `user`.id  
主表 user   子表  user_score   
關係    user_score.user_id = `user`.id

7 distinct，去掉重複值(貌似只對乙個字段有效？)

select

distinct company from orders

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