R help - Dec 2009 - The RSQLite version of dbGetQuery drops colums

Hi all,

I just noticed (the hard way of course) that when a query returns 0 
rows, the columns in the resulting data.frame get dropped as well. See 
the following example code (where conn is an active connection to an 
SQLite db):

 > dbGetQuery(conn, "select 1 as hey, 2 as ho where 1")
   hey ho
1   1  2
 > dbGetQuery(conn, "select 1 as hey, 2 as ho where 0")
data frame with 0 columns and 0 rows

I believe that the second query should return a 0x2 data.frame instead, 
that is, the same value as:

 > dbGetQuery(conn, "select 1 as hey, 2 as ho where 1")[FALSE,]
[1] hey ho
<0 rows> (or 0-length row.names)

Any thoughts? Is this a bug, and are the developers of RSQLite reading this?

Best regards,
Magnus

Hi  Magnus,

Magnus Torfason <zulutime.net <at> gmail.com>
writes:
> I just noticed (the hard way of course) that when a query returns 0 
> rows, the columns in the resulting data.frame get dropped as well. See 
> the following example code (where conn is an active connection to an 
> SQLite db):
> 
>  > dbGetQuery(conn, "select 1 as hey, 2 as ho where 1")
>    hey ho
> 1   1  2
>  > dbGetQuery(conn, "select 1 as hey, 2 as ho where 0")
> data frame with 0 columns and 0 rows
> 
> I believe that the second query should return a 0x2 data.frame instead, 
> that is, the same value as:
I agree that keeping the column dimension is sensible.  I will see
about fixing that for the next release.
> Any thoughts? Is this a bug, and are the developers of RSQLite
> reading this?
A much better forum for RSQLite issues is the r-sig-db list.

+ seth