How can I extract the month using sqldf package

Question

I tried to get a view that is based on group by of date by using sqldf package and a month function but I got an error :Error in sqliteSendQuery(con, statement, bind.data)

Answer 1

I suspect you are used to SQL Server, but the sqldf backend being used in your case is SQLite, where there is no MONTH function. Try this instead:

R> sqldf("SELECT strftime('%m', dateTime) AS Month
            ,SUM(wolfs) AS Wolves
         FROM df
         GROUP BY strftime('%m', dateTime)")
#    Month Wolves
#  1    01      6
#  2    02      5
#  3    03      3
#  4    04     12
#  5    05      7
#  6    08      7
#  7    09      7

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