Failed to connect the database when using sqldf in r

Question

I loaded a csv file to my R, and when I Tried to use sqldf to select some column, it always went to

Error in .local(drv, ...) : 
  Failed to connect to database: Error: Access denied for user 
  'User'@'localhost' (using password: NO)
Error in !dbPreExists : invalid argument type

I don't know how to fix it.

Here is my script:

library("RMySQL")
library(sqldf)
acs<-read.csv("getdata_data_ss06pid.csv",head = T)
sqldf("select pwgtp1 from acs where AGEP < 50")

Answer 1

It doesn't seem like you need to load the RMySQL library when using sqldf, since you have already read the data into memory, which seems to be the problem here:

library(RMySQL)
library(sqldf)
sqldf("select * from df limit 6")

Error in .local(drv, ...) : Failed to connect to database: Error: Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2) Error in !dbPreExists : invalid argument type

However if RMySQL library is detached, sqldf works:

detach("package:RMySQL", unload=TRUE)
sqldf("select * from df limit 6")
#   time  type
# 1    1 type1
# 2    2 type1
# 3    3 type2
# 4    4 type1
# 5    5 type2
# 6    6 type1