how to order 2 SQL Fields in asc and desc dynamically

Question

I want to Order a SQL Select Query where there\'s 2 fields that are in the order by. I then need to decide if one is Descending and the other as Ascending. How is this done<

Answer 1

Here is the solution

Explanation:
1. Ordering the row number on the basis of SQL input param  order by (DESC, ASC)
2. Againt ordering the row number in outer query

Try this code (working)

DECLARE @PageNum int
DECLARE @PageSize int
DECLARE @TotalRowsNum int
DECLARE @SortColumn varchar(200)
DECLARE @SortOrder varchar(5)

SET @PageNum = 4;
SET @PageSize = 10;
SET @SortColumn = 'CODE_ID';
SET @SortOrder = 'DESC';

WITH QueryResult AS
(

SELECT *,
CASE @SortOrder WHEN 'ASC' THEN
ROW_NUMBER() OVER(ORDER BY @SortColumn ASC) 
ELSE
ROW_NUMBER() OVER(ORDER BY @SortColumn DESC) 
END AS 'RowNumber'

FROM TABLE_NAME 
) 
SELECT * FROM QueryResult
WHERE RowNumber BETWEEN (@PageNum - 1) * @PageSize + 1 AND @PageNum * @PageSize
ORDER BY RowNumber ASC 

Answer 2

You will have to create your SQL statement dynamically in order to use a variable:

DECLARE @asc_desc VARCHAR(4);

SET @asc_desc = 'DESC';

DECLARE @sql NVARCHAR(1000);

SET @sql = 'Select * from Customer Order By Date ' + @asc_desc + ', Name';

EXEC sp_executesql @sql

This will order Date DESCENDING and Name ASCENDING.

You only need to add DESC if you want to use DESCENDING as ASCENDING is default.

Answer 3

SELECT 
  Customer_ID,                        
  Name,                               
  Age                                         
FROM
  #Customer
ORDER BY 
  CASE WHEN @field = 'Name' AND @direction = 'A' THEN Name ELSE NULL END ASC,
  CASE WHEN @field = 'Name' AND @direction = 'D' THEN Name ELSE NULL END DESC,
  CASE WHEN @field = 'Age'  AND @direction = 'A' THEN Age  ELSE NULL END ASC,
  CASE WHEN @field = 'Age'  AND @direction = 'D' THEN Age  ELSE NULL END DESC

I wouldn't want to do that over many different combinations though. If you have a lot of combinations I'd do somethign based on the following...

SELECT 
  Customer_ID,                        
  Name,                               
  Age                                         
FROM
(
  SELECT
    Customer_ID,
    Name,
    ROW_NUMBER() OVER (ORDER BY Name) AS "name_order",
    Age,
    ROW_NUMBER() OVER (ORDER BY Age)  AS "age_order"
  FROM
    #Customer
)
  AS [data]
ORDER BY 
  CASE @field1
    WHEN 'Name' THEN CASE @direction1 WHEN 'A' THEN name_order ELSE -name_order END
    WHEN 'Age'  THEN CASE @direction1 WHEN 'A' THEN age_order  ELSE -age_order  END
    ELSE NULL
  END,
  CASE @field2
    WHEN 'Name' THEN CASE @direction2 WHEN 'A' THEN name_order ELSE -name_order END
    WHEN 'Age'  THEN CASE @direction2 WHEN 'A' THEN age_order  ELSE -age_order  END
    ELSE NULL
  END

Repeat as many times as is required...

Note: Just because it can be done this way, doesn't mean it should be done this way.

Answer 4

In SQL Server 2005+ you could employ the following device:

WITH CustomerCTE AS (
  SELECT
    *,
    DateSort = ROW_NUMBER() OVER (ORDER BY Date),
    NameSort = ROW_NUMBER() OVER (ORDER BY Name)
  FROM Customer
)
SELECT *
FROM CustomerCTE
ORDER BY DateSort * @DateSortDir, NameSort * @NameSortDir

The vars in this case should be either 1 or -1.

---

EDIT

The additionally posted example seems to imply that the order of columns to use in ORDER BY should be dynamical too. And it also now seems that the order direction is specified uniformly for both columns.

Whether it is so or not (the question has become a bit more ambiguous), both are assumed in my second solution.

DECLARE @IntSortDir int;
SET @IntSortDir = CASE @directionOfSort WHEN 'A' THEN 1 ELSE -1 END;

WITH CustomerCTE AS (
  SELECT
    Customer_ID,
    Name,
    Age,
    NameSort = ROW_NUMBER() OVER (ORDER BY Name),
    AgeSort  = ROW_NUMBER() OVER (ORDER BY Date)
  FROM Customer
)
SELECT
  Customer_ID,
  Name,
  Age
FROM CustomerCTE
ORDER BY
  CASE @fieldSort WHEN 'Age' THEN AgeSort END * @IntSortDir,
  NameSort * @directionOfSort,
  CASE @fieldSort WHEN 'Name' THEN AgeSort END * @IntSortDir

@fieldSort specifies the primary order column. The other one automatically becomes the secondary one.