[英]mysql sort field increment value with extra grouping
我損壞了 sort_order 字段,需要通過將行更新為增量順序來更正該字段。 當沒有分組時,此解決方案非常有效:
SET @i := 0;
UPDATE tbl SET sort_order= @i:=@i+1 ORDER BY sort_order;
但是,當您談論需要為每個組重置 sort_order 字段的表時,該解決方案將失敗。 就我而言,唯一組是用戶和類型的組合,因此應該為每個唯一用戶/類型組合重置 sort_order。
我能做些什么來更新這個:
id user type name sort_order
152070 cust forex ^EURUSD 3
374143 cust forex ^EURGBP 3
376218 cust stock IBM 3
376219 cust stock FB 3
376219 cust stock AMZN 3
374676 degr forex ^BTCUSD 3
376217 degr forex ^AUDJPY 3
376220 degr stock C 3
376221 degr stock AMZN 3
看起來像這樣:
id user type name sort_order
152070 cust forex ^EURUSD 1
374143 cust forex ^EURGBP 2
376218 cust stock IBM 1
376219 cust stock FB 2
376219 cust stock AMZN 3
374676 degr forex ^BTCUSD 1
376217 degr forex ^AUDJPY 2
376220 degr stock C 1
376221 degr stock AMZN 2
我也對 PHP 解決方案持開放態度。
編輯:
mysql 5.6
我發布的第一個解決方案的結果是,這不是預期的結果。 同樣,我想按組重置排序。
id user type name sort_order
152070 cust forex ^EURUSD 1
374143 cust forex ^EURGBP 2
376218 cust stock IBM 3
376219 cust stock FB 4
376219 cust stock AMZN 5
374676 degr forex ^BTCUSD 6
376217 degr forex ^AUDJPY 7
376220 degr stock C 8
376221 degr stock AMZN 9
該站點上有大量與行號模擬相關的答案,這里有另一個用於多表更新的答案。
drop table if exists t;
create table t
(id int , user varchar(20) , type varchar(20) , name varchar(20), sort_order int);
insert into t values
(152070 , 'cust' , 'forex' , '^EURUSD' ,3),
(374143 , 'cust' , 'forex' , '^EURGBP' ,3),
(376218 , 'cust' , 'stock' , 'IBM' ,3),
(376219 , 'cust' , 'stock' , 'FB' ,3),
(376219 , 'cust' , 'stock' , 'AMZN' ,3),
(374676 , 'degr' , 'forex' , '^BTCUSD' ,3),
(376217 , 'degr' , 'forex' , '^AUDJPY' ,3),
(376220 , 'degr' , 'stock' , 'C' ,3),
(376221 , 'degr' , 'stock' , 'AMZN' ,3);
update t join
(select t.*,
if(concat(user,type) <> @p, @rn:=1,@rn:=@rn+1) rownumber,
@p:= concat(user,type) p
from t
cross join (select @rn:=0,@p:='') r
order by user,type,id) s
on s.id = t.id
set t.sort_order = s.rownumber
;
select * from t;
--------+------+-------+---------+------------+
| id | user | type | name | sort_order |
+--------+------+-------+---------+------------+
| 152070 | cust | forex | ^EURUSD | 1 |
| 374143 | cust | forex | ^EURGBP | 2 |
| 376218 | cust | stock | IBM | 1 |
| 376219 | cust | stock | FB | 3 |
| 376219 | cust | stock | AMZN | 3 |
| 374676 | degr | forex | ^BTCUSD | 1 |
| 376217 | degr | forex | ^AUDJPY | 2 |
| 376220 | degr | stock | C | 1 |
| 376221 | degr | stock | AMZN | 2 |
+--------+------+-------+---------+------------+
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