Question

I’ll try to avoid describing the background here. I now have a query result (not a table) which contains rows like this:

ID      SP1     SP2     SP3     SP4     SP5    SP6     SP7     SP8
1       null    null    2500    1400    700    null    null    null

There may be leading and/or trailing null values around a section of non-null values (which represents a decreasing process actually). And what I want is like this:

ID      SP1     SP2     SP3     SP4     SP5    SP6     SP7     SP8
1       2500    2500    2500    1400    700    0       0       0

That means, to replace leading nulls with the first non-null value, and trailing nulls with 0.
Please advise. I’m working on SQL Server 2000.

Answer 1

SELECT
    ID,
    COALESCE(SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,0) as SP1,
    COALESCE(SP2,SP3,SP4,SP5,SP6,SP7,SP8,0) as SP2,
    COALESCE(SP3,SP4,SP5,SP6,SP7,SP8,0) as SP3,
    COALESCE(SP4,SP5,SP6,SP7,SP8,0) as SP4,
    COALESCE(SP5,SP6,SP7,SP8,0) as SP5,
    COALESCE(SP6,SP7,SP8,0) as SP6,
    COALESCE(SP7,SP8,0) as SP7,
    COALESCE(SP8,0) as SP8
FROM
    (<your existing query>) t

COALESCE takes a number of expressions, and returns the first non-null value.