SQL Server : nested stored procedure to update table values - sql-server

Question

I have a table structure and its data as follows.
CREATE TABLE TestTable
(
id INT Identity(1,1) PRIMARY KEY,
creationTimestamp DATE,
indexOne INT,
indexTwo INT
);
INSERT INTO TestTable (creationTimestamp, indexOne, indexTwo)
VALUES
(2014-01-10, 100, 0),
(2014-01-11, 100, 0),
(2014-01-12, 100, 0),
(2014-01-13, 152, 2),
(2014-01-14, 152, 2),
(2014-01-15, 152, 2),
(2014-02-12, 152, 2),
(2014-02-13, 152, 2),
(2014-02-14, 333, 4),
(2014-02-15, 333, 4),
(2014-02-16, 333, 4),
(2014-03-10, 333, 4),
(2014-03-11, 333, 4),
(2014-03-12, 333, 4),
(2014-03-13, 333, 4),
(2014-03-14, 333, 4),
(2014-04-20, 500, 7),
(2014-04-21, 500, 7),
(2014-04-22, 500, 7),
(2014-04-23, 500, 7);
When you consider indexOne + indexTwo, there are duplicate rows. But I need them to be unique.
Therefore indexTwo must be properly indexed as follows
(2014-01-10, 100, 0),
(2014-01-11, 100, 1),
(2014-01-12, 100, 2),
(2014-01-13, 152, 0),
(2014-01-14, 152, 1),
(2014-01-15, 152, 2),
(2014-02-12, 152, 3),
(2014-02-13, 152, 4),
(2014-02-14, 333, 0),
(2014-02-15, 333, 1),
(2014-02-16, 333, 2),
(2014-03-10, 333, 3),
(2014-03-11, 333, 4),
(2014-03-12, 333, 5),
(2014-03-13, 333, 6),
(2014-03-14, 333, 7),
(2014-04-20, 500, 0),
(2014-04-21, 500, 1),
(2014-04-22, 500, 2),
(2014-04-23, 500, 3);
I have written the following stored procedure and it does not work properly
declare #indexOne int, #indexTwo int, #x int
declare c cursor for
select indexOne, indexTwo
from TestTable
group by indexOne, indexTwo
open c
fetch next from c into #indexOne, #indexTwo
while ##FETCH_STATUS = 0
begin
set #x = 0;
declare #id int
declare c1 cursor for
select id
from TestTable
where indexOne = #indexOne and indexTwo = #indexTwo
order by creationTimestamp asc
open c1
fetch next from c1 into #id
while ##FETCH_STATUS = 0
begin
UPDATE TestTable SET indexTwo = #x WHERE id = #id
set #x = #x + 1
fetch next from c1 into #id
end
close c1
deallocate c1
fetch next from c into #indexOne, #indexTwo
end
close c
deallocate c
Help me to find why this is not working

Answer 1

You don't need a cursor to do this use window function to generate the indextwo values per creationtimestamp, indexone. I hope this will do the job.
Sql Server
UPDATE A
SET indexTwo = b.indexTwo
FROM testtable a
JOIN (SELECT creationTimestamp, indexOne,
Row_number()OVER(partition BY indexone
ORDER BY creationtimestamp)-1 indexTwo
FROM testtable) B
ON a.creationtimestamp = b.creationtimestamp
AND a.indexone = b.indexone
SQLFIDDLE DEMO