I am using RMySQL package to write (append) data in current table.
I am using R, version 3.3.2.
My code looks like this:
library(RMySQL)
df_final <- some_data
m<-dbDriver("MySQL")
mydb <- dbConnect(m, user='odvjet12_mislav',
password='my_pass',
host='91.234.46.219',
dbname='odvjet12_fina_pn')
dbWriteTable(mydb, value = df_final, name = "fina_pn", append = TRUE, row.names = FALSE)
This code works fine for some time, but in last ten days, it always return an error:
Error in .local(conn, statement, ...) :
could not run statement: The used command is not allowed with this MySQL version
I don't understand how it is possible for code to work for some time and now, it returns an error?
I kindly ask for feedback on this issue.
Best,
Mislav Šagovac
You could also use dbGetQuery from the RMySQL package and iterate over the rows, which was my solution when I reached a similar error for a dataframe I wanted to write to a MySQL DB:
mydb = dbConnect(MySQL(), user='user', password='password', dbname='databasename', host='hostname')
for(i in 1:nrow(df)){
dbGetQuery(mydb,paste0("INSERT INTO MYTABLE (COL1,COL2) VALUES(",df$col1[i],",",df$col2[i],")"))
}
Related
This question expands on this question
Here, I'm using the custom function created by #Simon.S.A. shown in the answer to this question. I'm attempting to save a tbl_sql object in R to MySQL as a new table without first saving it locally. Here, the database and schema in my MySQL are named "test." The tbl_sql object in R is my_data, and I want to save this is a new table in MySQL labeled "car_data".
library(DBI)
library(tidyverse)
library(dbplyr)
#establish connection and import data from MySQL
con <- DBI::dbConnect(RMariaDB::MariaDB(),
dbname = "test",
host = "127.0.0.1",
user = "user",
password = "password")
my_data <- tbl(con, "mtcars")
my_data <- my_data %>% filter(mpg >= 22)
# write function to save tbl_sql as a new table in SQL
write_to_database <- function(input_tbl, db, schema, tbl_name){
# connection
tbl_connection <- input_tbl$src$con
# SQL query
sql_query <- glue::glue(
"SELECT *\n",
"INTO {db}.{schema}.{tbl_name}\n",
"FROM (\n",
dbplyr::sql_render(input_tbl),
"\n) AS sub_query"
)
result <- dbExecute(tbl_connection, as.character(sql_query))
}
# execute function
write_to_database(my_data, "test", "test", "car_data")
After running final line, I get the following error. I'm not sure how I can fix this.
Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.test.car_data
FROM (
SELECT *
FROM `mtcars`
WHERE (`mpg` >= 22.0)
) AS sub_quer' at line 2 [1064]
12.
stop(structure(list(message = "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.test.car_data\nFROM (\nSELECT *\nFROM `mtcars`\nWHERE (`mpg` >= 22.0)\n) AS sub_quer' at line 2 [1064]",
call = NULL, cppstack = NULL), class = c("Rcpp::exception",
"C++Error", "error", "condition")))
11.
result_create(conn#ptr, statement, is_statement)
10.
initialize(value, ...)
9.
initialize(value, ...)
8.
new("MariaDBResult", sql = statement, ptr = result_create(conn#ptr,
statement, is_statement), bigint = conn#bigint, conn = conn)
7.
dbSend(conn, statement, params, is_statement = TRUE)
6.
.local(conn, statement, ...)
5.
dbSendStatement(conn, statement, ...)
4.
dbSendStatement(conn, statement, ...)
3.
dbExecute(tbl_connection, as.character(sql_query))
2.
dbExecute(tbl_connection, as.character(sql_query))
1.
write_to_database(my_data, "test", "test", "car_data")
Creating a table with INTO command is an SQL Server (even MS Access) specific syntax and not supported in MySQL. Instead, consider the counterpart statement: CREATE TABLE...SELECT. Also, schema differs between RDBMS's. For MySQL, database is synonymous to schema.
Therefore, consider adjusted version of SQL build:
sql_query <- glue::glue(
"CREATE TABLE {db}.{tbl_name}\n AS \n",
"SELECT * \n",
"FROM (\n",
dbplyr::sql_render(input_tbl),
"\n) AS sub_query"
)
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
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)
I have a data frame containing columns 'Quarter' having values like "16/17 Q1", "16/17 Q2"... and 'Vendor' having values like "a", "b"... .
I am trying to write this data frame into database using
query <- paste("INSERT INTO cc_demo (Quarter,Vendor) VALUES(dd$FY_QUARTER,dd$VENDOR.x)")
but it is throwing error :
Error in .local(conn, statement, ...) :
could not run statement: Unknown column 'dd$FY_QUARTER' in 'field list'
I am new to Rmysql, Please provide me some solution to write entire dataframe?
To write a data frame to mySQL DB you need to:
Create a connection to your database, you need to specify:
MySQL connection
User
Password
Host
Database name
library("RMySQL")
connection <- dbConnect(MySQL(), user = 'root', password = 'password', host = 'localhost', dbname = 'TheDB')
Using the connection create a table and then export data to the database
dbWriteTable(connection, "testTable", testTable)
You can overwrite an existing table like this:
dbWriteTable(connection, "testTable", testTable_2, overwrite=TRUE)
I would advise against writing sql query when you can actually use very handy functions such as dbWriteTable from the RMySQL package. But for the sake of practice, below is an example of how you should go about writing the sql query that does multiple inserts for a MySQL database:
# Set up a data.frame
dd <- data.frame(Quarter = c("16/17 Q1", "16/17 Q2"), Vendors = c("a","b"))
# Begin the query
sql_qry <- "insert into cc_demo (Quarter,Vendor) VALUES"
# Finish it with
sql_qry <- paste0(sql_qry, paste(sprintf("('%s', '%s')", dd$Quarter, dd$Vendors), collapse = ","))
You should get:
"insert into cc_demo (Quarter,Vendor) VALUES('16/17 Q1', 'a'),('16/17 Q2', 'b')"
You can provide this query to your database connection in order to run it.
I hope this helps.
I am running an R script that adds data to mySQL database. I usually format the data and add it as as it comes in after couple of hours (data string is not continuous). My first set of data was added properly in MySQL database. The second string of data can not be added properly.
con = dbConnect(MySQL(), user='root', password='xxxxxx', dbname='test', host='localhost')
dbWriteTable(con, 'Tables', value = parseTweets(filterStream(file.name= "", track=c("lebron"), timeout=10, oauth=my_oauth)))
When I rerun the last code (dbWriteTable) again, it gives me following error
Error: Error in .local(conn, statement, ...) :
could not run statement: Table 'tables' already exists
I also used
dbWriteTable(con, 'Tables', value = parseTweets(filterStream(file.name= "", track=c("lebron"), timeout=10, oauth=my_oauth)), append = TRUE)
but it provides the same error
For some reason giving setting append to TRUE is not working. Instead give it a number. See the code below for better understanding
dbWriteTable(con, 'Tables', value = parseTweets(filterStream(file.name= "", track=c("lebron"), timeout=100, oauth=my_oauth)), overwrite = 0, row.names = 0, append = 1)
I am trying to fetch symbols from a MySQL db using getSymbols, however the following code
library(blotter)
library(DBI)
library(RMySQL)
setDefaults(getSymbols.MySQL,user="****", password="****", dbname="quantmoddb")
currency("USD")
stock("myspy",currency="USD",multiplier=1)
getSymbols("myspy",src="MySQL")
throws
Error in (function (classes, fdef, mtable) :
unable to find an inherited method for function ‘dbConnect’ for signature ‘"character"’
I am pretty sure the db is set up correctly as the following code runs fine and returns the dataset as expected.
con <- dbConnect(RMySQL::MySQL(),user="****",password="****", dbname="quantmoddb",
host="localhost", port=3306)
db.Symbols <- DBI::dbListTables(con)
query <- paste("SELECT * from myspy ORDER BY date")
rs <- DBI::dbSendQuery(con, query)
fr <- DBI::fetch(rs, n=-1)
Any help is greatly appreciated!
The "character" method for dbConnect was removed in the 0.10 release of RMySQL. I'm not sure whether or not this was intentional. It was not mentioned in the release notes.