如何在不影响其他值的情况下获取空值来代替序列中已删除的行 [英] How to obtain null values in place of deleted rows in a sequence without affecting other values

问题描述

create table missing_data(sno varchar(3)primary key,name varchar(15),designation char(10))

insert into missing_data values(1,'riz','SE'),(2,'sandy','SE'),(3,'sharein','SE'),(4,'chithu','SE'),(5,'flora','SE'),(6,'gayu','SD'),(7,'maha','SD'),(8,'moni','SD'),(9,'maddy','AE'),(10,'naz','AE')

select * from missing_data order by sno

delete from missing_data where name='gayu' 

我尝试了什么：



我在上面删除了name ='gayu'表和我希望sno = 6在使用null va删除后出现在表上行中的lues不会影响序列..这可能在sql表中???

What I have tried:

I had deleted name='gayu' in the above table and i want sno = 6 to appear on the table after delete with null values in the row without affecting sequence.. is that possible in sql table???

推荐答案

你永远不想重用ID。如果删除一行，那么该ID就会消失，再次使用它是非常糟糕的做法。相反，如果您不想删除它，请添加名为deleted_time的字段并存储删除的时间。然后在检索数据时过滤掉那些。

You don't ever want to reuse Ids. If you delete a row then that ID is gone and it is very bad practice to use it again. Instead, if you don't really want it deleted, add a field named deleted_time and store the time it is deleted. Then filter those out when retrieving your data.

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