Convert from varchar to decimal


hi all

i have a field which is stored as a varchar(30). I need it as varchar as the value can be characters or numbers etc.

in some case i  need to add two of these fields when the text value are deciamls e.g. '.75' to do this i need to change them to decimals first. i have tried Cast('0.75' as DECIMAL(28,9)) but it gives me 1.00000000. it seems to be rounding to the nearest whole number. can anyone help?
CauseAsked:
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Greg RowlandSoftware Designer, SysDBA, WebMaster OwnerCommented:
declare @aNumber DECIMAL(28,9)

set @aNumber =  Cast('0.759' as DECIMAL(28,9))

SELECT @aNumber
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DexstarCommented:
What SurferJoe posted should work.  You shouldn't issue Cast('0.75' as DECIMAL(28,9)) and get 1.000000 unless there is some other conversion going on.  Post your SELECT statement, and we can help determine that.

But from what you've mentioned, I think you need a more robust solution.  For example, if you have 2 fields in a table, and you want to return the sum of those fields if they are numeric, then try something like this:

SELECT Value = CASE
            WHEN ISNUMERIC(Field1) = 1 THEN CAST(Field1 AS DECIMAL(28,9))
            ELSE 0 END
            +
            CASE WHEN ISNUMERIC(Field2) = 1 THEN CAST(Field2 AS DECIMAL(28,9))
            ELSE 0 END
FROM Table

(Where Field1 and Field2 are your VARCHAR fields and Table is your table)
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CauseAuthor Commented:

Thanks SurferJoe that worked!

Thanks as well  Dexstar! i had implemented the other answer before i saw urs :-( as you poined out another field in the statment had an incorrect conversion!

Thanks again
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