It's possible to have and update (T-SQL) to fill the empty rows with the previous value, until find a row with value

That's the column, I would like to write the "May 24, 2022", until the value "May 23,2022" and then "May 23,2022" until the next not NULL column

Thanks in advance.

CodePudding user response：

One possibility is to use a correlated subquery in an update:

update t 
  set date = (select min(date) from t t2 where t2.id < t.id)
where date is null

Demo Fiddle

CodePudding user response：

We would like to use last_value but ignore nulls doesn't work in SQL Server.
We can use a CTE and inline sub-query.

create table t(id int, date_ varchar(10));
insert into t values (1,'2022-05-24'),(8,'2022-05-23');
insert into t (id) values(2),(3),(4),(5),(6),(7),(9),(10);

10 rows affected

with cte as(
select 
  id, 
  date_,
  (select max(id) from t t2 where t2.id <= t.id and date_ is not null ) idd
from t)
select
  id,
  (select date_ from cte c where c.id = d.idd) "date"
from cte d
order by id

id | date      
-: | :---------
 1 | 2022-05-24
 2 | 2022-05-24
 3 | 2022-05-24
 4 | 2022-05-24
 5 | 2022-05-24
 6 | 2022-05-24
 7 | 2022-05-24
 8 | 2022-05-23
 9 | 2022-05-23
10 | 2022-05-23

db<>fiddle here