some data prep stuff for pushing R variables to SQL queries

sql_r_stuff.R

# for passing multiple variables to SQL in() queries

ids <- c(1,2,3)
idstring <- paste(ids, collapse=", ")
idstring <- paste0("'", idstring, "'")

#for a string of characters:
idch <- c("1", "2", "3")
idchstring <- paste0("'", idch, "'")
idchstring <- toString(idchstr)

A DBI call would then look like e.g.

qry <- dbGetQuery(con, paste0("select * from table where colname in (", idstring, ")"))
qry <- dbGetQuery(con, paste0("select * from table where colname in (", idchstring, ")"))

# in both cases I usually source the inputs from a data frame column e.g. ids <- df$col
# in that case its generally a good idea to run ids through unique() first