[R] RSQLite does not read very large values correctly

jim holtman jholtman at gmail.com
Mon Nov 30 18:31:49 CET 2009


It appears that you were reading the number in as an integer and not
numeric.  The value that you are seeing (-596864072) is the numeric
value trucated to 32 bit.  The number would have been in hex
(6DC6C93B8) but dropping the leading '6' you will get the result as a
32 bit integer.  Check your data base definition and how you are
reading in your data.

On Mon, Nov 30, 2009 at 11:14 AM, Ruecker, Sebastian
<Sebastian.Ruecker at commerzbank.com> wrote:
> Hello,
>
> I am trying to import data from an SQLite database to R.
> Unfortunately, I seem to get wrong data when I try to import very large
> numbers.
>
> For example:
> I look at the database via SQLiteStudio(v.1.1.3) and I see the following
> values:
>
> OrderID Day             TimeToclose
> 1               2009-11-25      29467907000
> 2               2009-11-25      29467907000
> 3               2009-11-25      29467907000
>
>
> Now I run this R Code:
>
>> library("DBI")
>> library("RSQLite")
>>
>> # DB Connection
>> con <- dbConnect(dbDriver("SQLite"), "C:/Temp/TickDB01.db")
>> raw_Data <- dbGetQuery(con, "SELECT OrderID, Day, TimeToClose FROM
> Tr_TickData WHERE OrderID in (1,2,3)")
>> raw_Data
>  OrderID        Day TimeToClose
> 1       1 2009-11-25  -596864072
> 2       2 2009-11-25  -596864072
> 3       3 2009-11-25  -596864072
>
>
> The values are totally wrong... Is it because RSQLite has a problem with
> big numbers?
> TimeToClose is microseconds till 17:00.
>
> When I make the numbers smaller, it works again:
>
>> raw_Data <- dbGetQuery(con, "SELECT TimeToClose/1000 as TTC FROM
> Tr_TickData WHERE OrderID in (1,2,3)")
>> raw_Data
>       TTC
> 1 29467907
> 2 29467907
> 3 29467907
>
>
> I would appreciate any help with this problem!
>
> Thanks and regards,
>
> Sebastian
>
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?



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