loop through rows and delete those with a specific value - sql

Question

I have a question. I have for example this table in database:
row column visible
-----------------------
1 1 no
1 2 no
1 3 no
1 4 no
2 1 yes
2 2 yes
2 3 yes
2 4 yes
I want to loop through this table and to verify if all the rows have visibility "no". If all the row have the visibility no, I want that my new table to be :
row column visible
-----------------------
1 1 yes
1 2 yes
1 3 yes
1 4 yes
I am thinking at a cursor in a stored procedure like this:
create procedure someProcedure
as
declare #visible varchar(5)
declare #column int
declare #position int
declare scan cursor for
select column, position, visible
from table
where row between (select min(row) from table)
and (select max(row) from table)
order by row, column
but i don't know how to do this, I'm very new to sql,thank you

Answer 1

Cursors are slow and inefficient, and are very rarely needed. You don't need a cursor for this, you can use an updatable CTE to update the yes rows.
CREATE OR ALTER PROCEDURE someProcedure
AS
WITH cte AS (
SELECT *,
AnyVisible = COUNT(CASE WHEN Visible = 'yes' THEN 1 END) OVER (PARTITION BY row)
FROM [table] t
)
DELETE FROM cte
WHERE AnyVisible = 0;
WITH cte AS (
SELECT *,
rn = DENSE_RANK() OVER (ORDER BY row)
FROM [table] t
)
UPDATE cte
SET row = rn;
GO

Answer 2

I am not a 100% sure what you are trying to achieve but here is a small template for the cursor.
create procedure someProcedure as
declare #column int
declare #position int
declare #visible varchar(5)
declare scan cursor for
select column, position, visible
from table
where row between (select min(row) from table)
and (select max(row) from table)
order by row, column
--Open the cursor
open scan
-- fill variables with first position of cursor
fetch next from scan into #column, #position, #visible
-- start looping unit end
while(##FETCH_STATUS = 0)
begin
/*
Do things here
*/
-- move to next position in cursor
fetch next from scan into #column, #position, #visible
end
close scan
deallocate scan