sqldf

I am working on families trees : I have adapted Bob Horton's example based on sqldf https://www.r-bloggers.com/exploring-recursive-ctes-with-sqldf/ My data : person father Guillou Arthur NA Cleach Marc NA Guillou Eric Guillou Arthur Guillou Jacques Guillou Arthur Cleach Franck Cleach Marc Cleach Leo Cleach Marc Cleach Herbet Cleach Leo Cleach Adele Cleach Herbet Guillou Jean Guillou Eric Guillou Alan Guillou Eric My results, descendants ordered by levels of "Guillou Arthur" (top person without father) : name parent_name level Guillou Arthur NA 1 Guillou Eric Guillou Arthur 2 Guillou Jacques

I have a problem with SQLdf. Although I am trying to update a table, it always gives NULL as an output. I red things about this problem but I cannot figure out how to solve it. My code is: fn$sqldf("update cons set V1='%$numbernew%' where V1=$'contact'") But after I check it to see if something has changed, all are the same as in the beginning. Any ideas would help. As Joran mentioned in a comment this question is an sqldf FAQ. In fact its sqldf FAQ #8 . As discussed there the problem is that you asked to update the table but never asked it to return the table. Also $'contract' should be '

I am used to writing data manipulation logic in SQL and now that I am learning R I find myself sometimes just wanting to do something that would be simple in SQL but I have to learn a bunch of stuff with R to do the same manipulation on an R data frame. Is there a simple work around? look at the package sqldf. http://code.google.com/p/sqldf/ It seems perfect for your needs. Josh Reich I'm also more comfortable with SQL, but when working with large data sets in R, my favourite manipulation tool is the data.table package. Unlike sqldf , which lets you write SQL in R, data.table lets you write R

I am wondering if it is possible to call an SQL function within an R function? Say for example that I have this dummy data and SQL function written in Postgres 9.3 CREATE TABLE tbl ( id VARCHAR(2) PRIMARY KEY ,name TEXT ,year_born NUMERIC ,nationality TEXT ); INSERT INTO tbl(id, name, year_born, nationality) VALUES ('A1','Bill',2001,'American') ,('B1','Anna',1997,'Swedish') ,('A2','Bill',1991,'American') ,('B2','Anna',2004,'Swedish') ,('B3','Anna',1989,'Swedish') ,('A3','Bill',1995,'American'); CREATE FUNCTION retrieve_data(TEXT) RETURNS TABLE ( id VARCHAR(2), name TEXT, year_born NUMERIC,

Is it possible to add comments inside the string in sqldf? Something like: sqldf('select ProductID, count(distinct SalePrice) as num_regPz from MYDF where SalesFlag=0 # coded value to identify regular prizes group by ProductID') Here "# coded value to identify regular prizes" is meant as a comment, and not as a part of the select statement. Comments in SQL use this format: /* Comment goes here */ If you change your code to the following then it should work sqldf('select ProductID, count(distinct SalePrice) as num_regPz from MYDF where SalesFlag=0 /* coded value to identify regular prizes */

I have a vector lims, with the limits of a score: [1] 0.000000 7.025894 9.871630 12.411131 15.155998 18.099176 21.431354 25.391163 30.616550 40.356630 I create a table to classify other clients with: lims[1]<- -0.00001 a<-data.frame(lims[2:10]) colnames(a)<-'maxSc' a<-rbind(a, 100) lims<-data.frame(lims) lims$maxSc<-a colnames(lims)<-c('minSc', 'maxSc') > class(lims) [1] "data.frame" So my result is: > lims minSc maxSc 1 -0.000010 7.025894 2 7.025894 9.871630 3 9.871630 12.411131 4 12.411131 15.155998 5 15.155998 18.099176 6 18.099176 21.431354 7 21.431354 25.391163 8 25.391163 30.616550 9 30