sql - new column each row results from a query to mysql database in R -

i've got simple dataframe 3 columns. 1 of columns contains database name. first need check if data exists, , if not, insert it. otherwise nothing.

sample data frame:

clientid;region;database 135;europe;europedb 2567;asia;asiadb 23;america;americadb 

so created function apply dataframe way:

library(rmysql)      check_if_exist <- function(df){      con <- dbconnect(mysql(),                        user="myuser", password="mypass",                        dbname=df$database, host="myhost")      query <- paste0("select count(*) table client_id='", df$clientid,"' , region='", df$region ,"'")      rs <- dbsendquery(con, query)      rs      } 

function call:

df$new_column <- lapply(df, check_if_exist) 

but doesn't work.

this working example of asking, if understood correctly. don't have database, print query verification, , fetch random number result.

note doing lapply(df,...), looping on columns of database, , not rows want.

df = read.table(text="clientid;region;database 135;europe;europedb 2567;asia;asiadb 23;america;americadb",header=t,sep=";")   check_if_exist <- function(df){   query = paste0("select count(*) table client_id='", df$clientid,"' , region='", df$region ,"'")   print(query)   rs <- runif(1,0,1)   return(rs) }  df$new_column <- sapply(split(df,seq(1,nrow(df))),check_if_exist) 

hope helps.