CODEWITHSUNDEEP
mysqlrrmysql
Prasinus Albus
Prasinus Albus

Reputation: 416

RMySQL: Error in as.character.default() :

I am trying to use the following function in R:

 heritblup <-  function(name) {
      library(RMySQL)
      library(DBI)
      con <- dbConnect(RMySQL::MySQL(),
                       dbname ="mydab",
                       host      = "localhost",
                       port  = 3306,
                       user  = "root",
                       password = "")
      value1 <- 23;
      rss<- paste0 ("INSERT INTO namestable 
                    (myvalue, person) 
                    VALUES ('$value1', '",name,"')")
      rs <<- dbGetQuery (con, rss)
    }

heritblup("Tommy")

But I keep getting this error:

Error in as.character.default() : no method for coercing this S4 class to a vector Called from: as.character.default()

I tried to change the paste function to this: rss<- paste0 ("INSERT INTO namestable (myvalue, person) VALUES ($value1, ",name,")")

the error persists; I have no idea whats wrong. Please help

Upvotes: 1

Views: 306

Answers (1)

MKR
MKR

Reputation: 20085

Couple of issues in code. I'm not sure if OP is attempting to insert records in database or fetch from database.

Assuming, based on query that he is expecting to insert data in database table.

The rule is that query should be prepared in R the way it will be executed in MySQL. Value replacement (if any) should be performed in R as MySQL engine will not have any idea about variables from R.

Hence, the query preparation steps should be done as:

rss <- sprintf("INSERT INTO namestable (myvalue, person) VALUES (%d, '%s')", value1, name)
# "INSERT INTO namestable (myvalue, person) VALUES (23, 'test')"

If data insert is goal then dbGetQuery is not right option per R documentation instead dbSendStatement() should be used for data manipulation. The reference from help suggest:

However, callers are strongly encouraged to use dbSendStatement() for data manipulation statements.

Based on that query execution line should be:

rs <- dbSendStatement(con, rss)
ret_val <- dbGetRowsAffected(rs)
dbClearResult(rs)
dbDisconnect(con)
return(ret_val)

Upvotes: 1

Related Questions