SQL Server：根据列值将行拆分为多行

Question

I have a question regarding splitting rows based on column value

My example data set is :

id   ExpenseType   Price
------------------------
 1   Car           100
 2   Hotel          50

I want to split rows those have some Expense Types such as Car into two rows . Others should remain as one row.

First row Price *70 
Second Row Price *30 

Returned dataset should be

id   ExpenseType  Price
-----------------------
 1   Car           70 
 1   Car           30 
 2   Hotel         50

Thanks for your answers in advance

Answer 1

I have a question regarding splitting rows based on column value

My example data set is :

id   ExpenseType   Price
------------------------
 1   Car           100
 2   Hotel          50

I want to split rows those have some Expense Types such as Car into two rows . Others should remain as one row.

First row Price *70 
Second Row Price *30 

Returned dataset should be

id   ExpenseType  Price
-----------------------
 1   Car           70 
 1   Car           30 
 2   Hotel         50

Thanks for your answers in advance

Answer 2

I have a question regarding splitting rows based on column value

My example data set is :

id   ExpenseType   Price
------------------------
 1   Car           100
 2   Hotel          50

I want to split rows those have some Expense Types such as Car into two rows . Others should remain as one row.

First row Price *70 
Second Row Price *30 

Returned dataset should be

id   ExpenseType  Price
-----------------------
 1   Car           70 
 1   Car           30 
 2   Hotel         50

Thanks for your answers in advance

Answer 3

I have a question regarding splitting rows based on column value

My example data set is :

id   ExpenseType   Price
------------------------
 1   Car           100
 2   Hotel          50

I want to split rows those have some Expense Types such as Car into two rows . Others should remain as one row.

First row Price *70 
Second Row Price *30 

Returned dataset should be

id   ExpenseType  Price
-----------------------
 1   Car           70 
 1   Car           30 
 2   Hotel         50

Thanks for your answers in advance

Answer 4

I ran into a similar need, here is my solution.

Problem statement:
My organization is switching from an in-house build system to a third-party system. Numerical values in the original system surpassed the value size that the destination system could handle. The third-party system will not allow us to increase the field size, as a result we need to split the data up into values that do not surpass the field size limit.

Details: Destination system can only support values under 1 billion (can include a negative sign)

Example:

    DROP TABLE IF EXISTS #MyDemoData /* Generate some fake data for the demo */
            SELECT item_no = 1, item_description = 'zero asset',    amount = 0  INTO #MyDemoData
    UNION   SELECT item_no = 2, item_description = 'small asset',   amount = 5100000  
    UNION   SELECT item_no = 3, item_description = 'mid asset',     amount = 510000000  
    UNION   SELECT item_no = 4, item_description = 'large asset',   amount = 5100000000
    UNION   SELECT item_no = 5, item_description = 'large debt',    amount = -2999999999.99  
    

    SELECT * FROM #MyDemoData

    DECLARE @limit_size INT = 1000000000

    DROP TABLE IF EXISTS #groupings;
    WITH 
        max_groups AS 
            (   
                SELECT max_groups=100
            )
        ,groups AS 
            (
                SELECT 1 AS [group]
                UNION ALL
                SELECT [group]+1 
                FROM groups
                JOIN  max_groups ON 1=1 
                WHERE [group]+1<=max_groups
            )   
        ,group_rows AS 
            (
                SELECT 0 AS [row]
                UNION ALL
                SELECT [row]+1 
                FROM group_rows
                JOIN  max_groups ON 1=1 
                WHERE [row]+1<=max_groups
            )
        ,groupings AS
            (
                SELECT      [group],[row]
                FROM        group_rows
                CROSS JOIN  groups
                WHERE       [row] <= [group]
            )

        SELECT * INTO #groupings FROM groupings;

    WITH /* Split out items that are under the limit and over the limit */
        
        t1 AS /* Identify rows that are over the limit and by how many multiples over it is */
            (
                SELECT
                        item_no
                    ,   item_description    
                    ,   amount
                    ,   over_limit = FLOOR(ABS(amount/@limit_size))
                FROM    #MyDemoData
            )
    
    SELECT /* select the items that are under the limit and do not need manipulated */
                item_no
            ,   item_description    
            ,   amount = CAST(amount AS DECIMAL(16,2))
    FROM        t1 
    WHERE       ABS([amount]) < @limit_size
    UNION ALL /* select the items that are over the limit, join on the groupings cte and calculate the split amounts */
    SELECT
                item_no
            ,   item_description    
            ,   [Amount] = CAST(
                    CASE 
                            WHEN row != 0 THEN (@limit_size-1) * ([amount]/ABS([amount]))   
                            ELSE (ABS([amount]) - (t1.over_limit * @limit_size) + t1.over_limit) * ([amount]/ABS([amount]))
                    END AS DECIMAL(16,2))
    FROM        t1 
    JOIN        #groupings bg ON t1.over_limit = bg.[group] 
    WHERE       ABS([amount]) >= @limit_size
    ORDER BY    item_no