SQL Server 2022

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CREATE TABLE pricedata ([from] INT, [to] INT, price INT)
INSERT pricedata
VALUES
    (2008, 2009, 100),
    (2009, 2011, 121),
    (2011, 2020, 142)
3 rows affected

CREATE PROC InsertPriceData (@InsertFrom INT, @InsertTo INT, @InsertPrice INT)
AS
    -- Delete any row completely superseded by new insert
    DELETE pricedata
    WHERE [from] >= @InsertFrom
    AND [to] <= @InsertTo 
  
    -- Duplicate and adjust any row split by new insert, leaving lower residual
    INSERT pricedata ([from], [to], price)
    SELECT [from], @InsertFrom, price
    FROM pricedata
    WHERE [from] < @InsertFrom
    AND [to] > @InsertTo 
    
    -- Adjust original row split by new insert, leaving upper residual
    UPDATE pricedata
    SET [from] = @InsertTo
    WHERE [from] < @InsertFrom
    AND [to] > @InsertTo 
    
    -- Trim lower end of row overlapping upper end of insert
    UPDATE pricedata
    SET [from] = @InsertTo
    WHERE [from] >= @InsertFrom
    AND [from] < @InsertTo 
    
    -- Trim upper end of row overlapping lower end of insert
    UPDATE pricedata
    SET [to] = @InsertFrom
    WHERE [to] > @InsertFrom
    AND [to] <= @InsertTo 

    -- Now that we have resolved any overlaps, we are clear to insert the new row
    INSERT pricedata ([from], [to], price)
    VALUES (@InsertFrom, @InsertTo, @InsertPrice)
SELECT * FROM pricedata ORDER BY [from]

EXEC InsertPriceData 2010, 2012, 109
SELECT * FROM pricedata ORDER BY [from]


from
to
price


2008
2009
100

2009
2011
121

2011
2020
142




from
to
price


2008
2009
100

2009
2010
121

2010
2012
109

2012
2020
142


-- More tests

EXEC InsertPriceData 2011, 2025, 999 -- Trim 109 and delete 142
SELECT * FROM pricedata ORDER BY [from]

EXEC InsertPriceData 2020, 2021, 888 -- Split 999
SELECT * FROM pricedata ORDER BY [from]

EXEC InsertPriceData 2011, 2015, 777 -- Trim first 999
SELECT * FROM pricedata ORDER BY [from]

EXEC InsertPriceData 2023, 2025, 666 -- Trim upper 999
SELECT * FROM pricedata ORDER BY [from]

EXEC InsertPriceData 2012, 2024, 555 -- Trim 777, delete 999/888/999, trim 666
SELECT * FROM pricedata ORDER BY [from]


from
to
price


2008
2009
100

2009
2010
121

2010
2011
109

2011
2025
999




from
to
price


2008
2009
100

2009
2010
121

2010
2011
109

2011
2020
999

2020
2021
888

2021
2025
999




from
to
price


2008
2009
100

2009
2010
121

2010
2011
109

2011
2015
777

2015
2020
999

2020
2021
888

2021
2025
999




from
to
price


2008
2009
100

2009
2010
121

2010
2011
109

2011
2015
777

2015
2020
999

2020
2021
888

2021
2023
999

2023
2025
666




from
to
price


2008
2009
100

2009
2010
121

2010
2011
109

2011
2012
777

2012
2024
555

2024
2025
666
from	to	price
2008	2009	100
2009	2010	121
2010	2011	109
2011	2020	999
2020	2021	888
2021	2025	999