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How to check if the column is int?

  • February 1, 2008 at 2:54 pm

    #120560

    Hi, All

    What's the easist way to check if a varchar column stores a number?

    Thanks

  • February 1, 2008 at 2:59 pm

    #774477

    Take a look at the IsNumeric() function. That should get you started.

  • February 1, 2008 at 3:03 pm

    #774480

    Great, thanks

  • February 1, 2008 at 3:39 pm

    #774492

    -- Convert to int if a valid integer

    select

    TestData,

    Output_INT =

    case

    when TestData like '-%[^0-9]%'then null

    when TestData not like '-%' and

    TestData like '%[^0-9]%' then null

    whenTestData not like '-%' and

    datalength(TestData) > 10then null

    whenTestData like '-%' and

    datalength(TestData) > 11then null

    whenconvert(bigint,TestData) between

    -2147483648 and 2147483647then convert(int,TestData)

    else null

    end

    from

    (

    -- Test data

    Select TestData = '1234a'union all

    Select TestData = '1234.'union all

    Select TestData = '12340'union all

    Select TestData = '-12340'union all

    Select TestData = '1234E'union all

    Select TestData = '1234'union all

    Select TestData = '-92233720368547758081'union all

    Select TestData = '9223372036854775808'union all

    Select TestData = '-2147483649'union all

    Select TestData = '-2147483648'union all

    Select TestData = '2147483647'union all

    Select TestData = '2147483648'

    ) a

    Results:

    TestData Output_INT

    --------------------- -----------

    1234a NULL

    1234. NULL

    12340 12340

    -12340 -12340

    1234E NULL

    1234 1234

    -92233720368547758081 NULL

    9223372036854775808 NULL

    -2147483649 NULL

    -2147483648 -2147483648

    2147483647 2147483647

    2147483648 NULL

    (12 row(s) affected)

  • February 1, 2008 at 5:55 pm

    #774502

    Pam Brisjar (2/1/2008)

    Take a look at the IsNumeric() function. That should get you started.

    Be careful, folks... IsNumeric allows for things like currency symbols, commas, periods, dashes, plus signs, and special scientific notation like 10E2 and 10D2. IsNumeric should never be used as an IsAllDigits function because it just doesn't work that way. You WILL need to use some LIKEs as Michael did above...

    --Jeff Moden

    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

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