[R] value changed after paste() function

[Bert Gunter]

Inline below.

On Mon, Mar 21, 2011 at 8:18 AM, kellysong <song.qiao at student.dit.ie> wrote:
> Hi all,
>
> I am new user in R, I am trying to to use paste function to concatenate
> strings which has been fetched from database table(postgres database), the
> following are my code:
>
> when i do:
>  > sqlFetch(channel,'transactions')
>
> outputs are following(only parts, there are around 200 transactions in
> total)
>
>    orderid productname price quantity discount
> 1    T10248      potato  1.80       10     0.00
> 2    T10248      sweets  2.00        5     0.00
> 3    T10249        milk  1.99        9     0.00
> 4    T10249       apple  2.35       40     0.00
>
>
> when i do:
>> paste(sqlFetch(channel,'transactions'))
>
> outputs are:
> [1] "c(1, 1, 2, 2)"
> [2] "c(7, 8, 6, 1)"
> [3] "c(1.8, 2, 1.99, 2.35) "
> [4] "c(10, 5, 9, 40)"
> [5] "c(0, 0, 0, 0) "
>
>
> any idea why the orderid and the productname have been changed?? and what

The results of sqlFetch is a data frame whose alphanumeric columns are
factors. You need to spend some (more) time with "An Introduction to
R" learning about R's data structures and basic procedures BEFORE you
start using it. After you have done so,

?do.call

and

?factor

will tell you how to deal with this sort of thing. But it is doubtful
that you will understand until you have first spent some time with the
basic docs.

-- Bert

> should i do to solve this??
>
> Any help would be very appreciated!
>
>
>
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>
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>



-- 
Bert Gunter
Genentech Nonclinical Biostatistics
467-7374
http://devo.gene.com/groups/devo/depts/ncb/home.shtml