Applying a sort order to existing data using SQL 2008R2
I have some existing data that I need to apply a "SortOrder" to based upon a few factors:
- The ordering starts at "1" for any given Owner
- The ordering is applied alphabetically (basically following an
ORDER BY Name
) to increase the sort order. - Should two items have the same name (as I've illustrated in my data set), we can apply the lower sort order value to the item with the lower id.
Here is some sample data to help illustrate what I'm talking about:
What I have:
Id OwnerId Name SortOrder
------ ------- ---------------------- ---------
1 1 A Name NULL
2 1 C Name NULL
3 1 B Name NULL
4 2 Z Name NULL
5 2 Z Name NULL
6 2 A Name NULL
What I need:
Id OwnerId Name SortOrder
------ ------- ---------------------- ---------
1 1 A Name 1
3 1 开发者_运维百科 B Name 2
2 1 C Name 3
6 2 A Name 1
4 2 Z Name 2
5 2 Z Name 3
This could either be done in the form of an UPDATE
statement or doing an INSERT INTO (...) SELECT FROM (...)
if it's easier to move the data from one table to the next.
Easy - use a CTE (Common Table Expression) and the ROW_NUMBER()
ranking function:
;WITH OrderedData AS
(
SELECT Id, OwnerId, Name,
ROW_NUMBER() OVER(PARTITION BY OwnerId ORDER BY Name, Id) AS 'SortOrder'
FROM
dbo.YourTable
)
SELECT *
FROM OrderedData
ORDER BY OwnerId, SortOrder
The PARTITION BY
clause groups your data into group for each value of OwnerId
and the ROW_NUMBER()
then starts counting at 1 for each new group of data.
Update: If you want to update your table to set the SortOrder
column - try this:
;WITH OrderedData AS
(
SELECT
Id, OwnerId, Name,
ROW_NUMBER() OVER(PARTITION BY OwnerId ORDER BY Name, Id) AS 'RowNum'
FROM
dbo.YourTable
)
UPDATE OrderedData
SET SortOrder = RowNum
That should set the SortOrder
column to the values that the ROW_NUMBER()
function returns
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