R help - Mar 2012 - Using extract function for dates in sqldf

I'm trying to use sqldf to query for the earliest date of a blood test when
patients have had multiple tests in a given year. My query looks like this:

test11 <- sqldf("select CHILD_ID, min(SAMP_DATE)
                 from lab
                 group by CHILD_ID
                 having extract (year from SAMP_DATE) = 2011")

SAMP_DATE has class "date." I get the error message

Error in sqliteExecStatement(con, statement, bind.data) :
  RS-DBI driver: (error in statement: near "from": syntax error)


The problem seems to be in the second "from" where the
"extract" function
is called. Does this need a fix or am I doing something wrong?

Thanks in advance and apologies if it turns out a simple error.

-M.L.

On Wed, Mar 21, 2012 at 11:31 AM,  <Michael.Laviolette at
dhhs.state.nh.us> wrote:
>
> I'm trying to use sqldf to query for the earliest date of a blood test
when
> patients have had multiple tests in a given year. My query looks like this:
>
> test11 <- sqldf("select CHILD_ID, min(SAMP_DATE)
> ? ? ? ? ? ? ? ? from lab
> ? ? ? ? ? ? ? ? group by CHILD_ID
> ? ? ? ? ? ? ? ? having extract (year from SAMP_DATE) = 2011")
>
> SAMP_DATE has class "date." I get the error message
>
> Error in sqliteExecStatement(con, statement, bind.data) :
> ?RS-DBI driver: (error in statement: near "from": syntax error)
extract is not supported by sqlite.  Check the SQLite date and time
functions link on the left side of the sqldf home page.  (The other
three databases supported by sqldf all do support extract.)

-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com