Sql 更新后记录的旧值和新值

我需要创建一个存储过程，它将找出更新记录的旧值和新值。 它应该包括用于在运行时查找列名的动态查询

我正在使用oracle 12C进行此操作

create table student (    
    id number(6) primary key,
    name varchar2(50),
    city varchar2(50),
    address varchar2(100),
    createdDateTime date,
    updatedDatetime date
);

insert into student values(1,'abc1','abc1','abc1','09-Jan-20','12-Jan-20');
insert into student values(2,'pqr','pqr','pqr','09-Jan-20',null);

学生桌-

ID      Name    City     Address    Create_time UpdatedTime
1       abc1    abc1     abc1       09-Jan-20   12-Jan-20
2       pqr     pqr      pqr        09-Jan-20   null

create table studentHistory (
    id number(6) ,
    name varchar2(50),
    city varchar2(50),
    address varchar2(100),
    DatetimeCreated date
);

insert into StudentHistory values(1,null,'abc',null,'10-Jan-20');
insert into StudentHistory values(1,'abc',null,null,'11-Jan-20');
insert into StudentHistory values(1,null,null,'abc','12-Jan-20');

学生历史表-

ID  Name    City        Address DatetimeCreated
1   null    abc          null     10-Jan-20
1   abc     null         null     11-Jan-20
1   null    null         abc      12-Jan-20

所需输出-->

---

我同意@stickybit。填充历史记录表实际上是一个起点。您应该创建@Littlefoot提到的触发器，以便在历史记录表中进行更新/插入，可以使用merge

但我只是根据您提供的数据尝试了一些东西，不要认为这是您要寻找的，但仍将其张贴在此处，因为它可能会在将来帮助其他人：

with name_cte
as
(
select 
a.id,
a.name as new_value,
b.name as old_value,
b.datetimecreated,
'name' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.name is not null
)
,city_cte
as
(
select 
a.id,
a.city as new_value,
b.city as old_value,
b.datetimecreated,
'city' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.city is not null
)
,address_cte
as
(
select 
a.id,
a.address as new_value,
b.address as old_value,
b.datetimecreated,
'address' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.address is not null
)
select 
a.id,
a.column_name,
a.old_value,
a.new_value,
a.datetimecreated as updatetime
from name_cte a
union all
select
b.id,
b.column_name,
b.old_value,
b.new_value,
b.datetimecreated as updatetime
from city_cte b
union all
select
c.id,
c.column_name,
c.old_value,
c.new_value,
c.datetimecreated as updatetime
from address_cte c

---

我同意@stickybit。填充历史记录表实际上是一个起点。您应该创建@Littlefoot提到的触发器，以便在历史记录表中进行更新/插入，可以使用merge

但我只是根据您提供的数据尝试了一些东西，不要认为这是您要寻找的，但仍将其张贴在此处，因为它可能会在将来帮助其他人：

with name_cte
as
(
select 
a.id,
a.name as new_value,
b.name as old_value,
b.datetimecreated,
'name' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.name is not null
)
,city_cte
as
(
select 
a.id,
a.city as new_value,
b.city as old_value,
b.datetimecreated,
'city' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.city is not null
)
,address_cte
as
(
select 
a.id,
a.address as new_value,
b.address as old_value,
b.datetimecreated,
'address' as column_name
from student a
join studenthistory b
on a.id=b.id
and b.address is not null
)
select 
a.id,
a.column_name,
a.old_value,
a.new_value,
a.datetimecreated as updatetime
from name_cte a
union all
select
b.id,
b.column_name,
b.old_value,
b.new_value,
b.datetimecreated as updatetime
from city_cte b
union all
select
c.id,
c.column_name,
c.old_value,
c.new_value,
c.datetimecreated as updatetime
from address_cte c

---

“我需要创建存储过程…”-不，您需要创建触发器，它们用于此目的。互联网上有无数的例子，做一些搜索，写一些代码。如果您无法使其正常工作，请返回-如果是，请编辑您的问题和您编写的post代码以及您遇到的错误。您应该将更新的旧值添加到历史记录表中。现在没有机会获得

更新的旧值，除非它是最后一个值。然后你只需要一个
选择
来获取旧值。“我需要创建存储过程…”-不，你需要创建一个触发器，它们用于这样的目的。互联网上有无数的例子，做一些搜索，写一些代码。如果您无法使其正常工作，请返回-如果是，请编辑您的问题和您编写的post代码以及您遇到的错误。您应该将更新的旧值添加到历史记录表中。现在没有机会获得
更新的旧值，除非它是最后一个值。然后，您只需选择
即可获得旧值。