Question

假设我有这些专栏

 uniqueID|Money|Quantity|MoneyOrder|QuantityOrder
1|23|12||
2|11|9||
3|99|100||

我想要做的是根据MoneyOrder的值更新QuantityOrder和ORDER BY。

结果将是：

uniqueID|Money|Quantity|MoneyOrder|QuantityOrder
1|23|12|2|1
2|11|90|1|2
3|99|100|3|3

我希望更新像标识列一样运行，而不是实际使其成为标识列。我知道我可以按'x'排序，订单就是结果，但我想生成一个报告，你可以逐行看到该项目。

这样的事情可能update mytable set Moneyorder = 'imnotsure' order by MoneyOrder asc吗？

Answer 1

SET @rownumber = 0;    
update mytable set Moneyorder = (@rownumber:=@rownumber+1)
order by MoneyOrder asc

或者在单个查询中执行此操作

update mytable target
join
(
     select id, (@rownumber := @rownumber + 1) as rownum
     from mytable         
     cross join (select @rownumber := 0) r
     order by MoneyOrder asc
) source on target.id = source.id    
set Moneyorder = rownum

Answer 2

查看这个问题的答案：

Updating column so that it contains the row position

SET @counter = 0;

UPDATE 
my_table
SET MoneyOrder = @counter := @counter + 1
ORDER BY Money;

SET @counter = 0;

UPDATE 
my_table
SET QuantityOrder = @counter := @counter + 1
ORDER BY Quantity;

mysql根据顺序更新一个带有int的列

2 个答案: