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I have a dataframe in R containing 10 rows and 7 columns. There's a stored procedure that does the few logic checks in the background and then inserts the data in the table 'commodity_price'.
library(RMySQL)
#Connection Settings
mydb = dbConnect(MySQL(),
user='uid',
password='pwd',
dbname='database_name',
host='localhost')
#Listing the tables
dbListTables(mydb)
f= data.frame(
location= rep('Bhubaneshwar', 4),
sourceid= c(8,8,9,2),
product= c("Ingot", "Ingot", "Sow Ingot", "Alloy Ingot"),
Specification = c('ie10','ic20','se07','se08'),
Price=c(14668,14200,14280,20980),
currency=rep('INR',4),
uom=rep('INR/MT',4)
)
For multiple rows insert, there's a pre-created stored proc 'PROC_COMMODITY_PRICE_INSERT', which I need to call.
for (i in 1:nrow(f))
{
dbGetQuery(mydb,"CALL PROC_COMMODITY_PRICE_INSERT(
paste(f$location[i],',',
f$sourceid[i],',',f$product[i],',',f$Specification[i],',',
f$Price[i],',',f$currency[i],',', f$uom[i],',',#xyz,')',sep='')
);")
}
I am repeatedly getting error.
Error in .local(conn, statement, ...) :
could not run statement: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '[i],',',
f$sourceid[i],',',f$product[i],',',f$Specification' at line 2
I tried using RODBC but its not getting connected at all. How can I insert the data from the R dataframe in the 'commodity_price' table by calling a stored proc? Thanks in advance!
That is probably due to your use of ', this might work:
for (i in 1:nrow(f))
{
dbGetQuery(mydb,paste("CALL PROC_COMMODITY_PRICE_INSERT(",f$location[i],',',
f$sourceid[i],',',f$product[i],',',f$Specification[i],',',
f$Price[i],',',f$currency[i],',', f$uom[i],',',"#xyz",sep='',");"))
}
or the one-liner:
dbGetQuery(mydb,paste0("CALL PROC_COMMODITY_PRICE_INSERT('",apply(f, 1, paste0, collapse = "', '"),"');"))
Trying the for loop:
for (i in 1:nrow(f))
{
dbGetQuery(mydb,paste("CALL PROC_COMMODITY_PRICE_INSERT(","'",f$location[i],"'",',',"'",
f$sourceid[i],"'",',',"'",f$product[i],"'",',',"'",f$Specification[i],"'",',',"'",
f$Price[i],"'",',',"'",f$currency[i],"'",',',"'",f$uom[i],"'",',','#xyz',sep='',");"))
}
When using dbReadTable to read in database tables that uses UUID as the primary key, I get the following warning message.
1: In postgresqlExecStatement(conn, statement, ...) :
RS-DBI driver warning: (unrecognized PostgreSQL field type uuid (id:2950) in column 0)
When I modify the table I loaded and try to update the database using, I get the following error message:
Error in postgresqlExecStatement(conn, statement, ...) :
RS-DBI driver: (could not Retrieve the result : ERROR: operator does not exist: uuid = text
I get that the UUID type is not available in R, but is there a way that we can make the database believe the character vector "unique_id" is UUID instead of text?
Code:
library(RPostgreSQL)
library(postGIStools)
pgdrv <- dbDriver(drvName = "PostgreSQL")
# === open connection
db <- DBI::dbConnect(pgdrv,
dbname="database",
host="localhost", port=5432,
user = 'postgres')
# === get tables
users <- dbReadTable(db, "app_users")
# === interaction with tables
users$employee_has_quit[1:5] <- TRUE
# === update tables
postgis_update(conn = db,
df = users,
tbl = "app_users",
id_cols = "unique_id",
update_cols = "employee_has_quit")
# === close conncetion
DBI::dbDisconnect(db)
The problem is a bug in postGIStools. You can see the code they're using to generate this error here
query_text <- paste(query_text, ") AS", tbl_tmp, "(",
paste(quote_id(colnames(df)), collapse = ", "), ")",
"WHERE", paste(paste0(tbl_q, ".", id_q), "=",
paste0(tbl_tmp, ".", id_q),
collapse = " AND "))
Simply put, that won't work. They should be suing placeholders. It assumes that the input type can be the result of make_str_quote (by proxy of df_q and quote_str). That's a faulty assumption as seen here,
CREATE TABLE foo ( a uuid );
INSERT INTO foo VALUES ( quote_literal(gen_random_uuid()) ) ;
ERROR: column "a" is of type uuid but expression is of type text
LINE 1: INSERT INTO foo VALUES ( quote_literal(gen_random_uuid()) ) ...
^
HINT: You will need to rewrite or cast the expression.
My suggestion is you follow the docs,
Note: This package is deprecated. For new projects, we recommend using the sf package to interface with geodatabases.
You may be able to work around this by doing this
CREATE CAST (varchar AS uuid)
WITH INOUT
AS IMPLICIT;
I am trying to delete data from R in mysql table with the data range
Actual statement :
dbSendQuery(conn,"delete from tab_name where date<='2018-07-29'")
tried with :
conn = dbConnect(MySQL(),user ="user_id",password = "pwd",dbname ="db_name",host ="localhost")
a="2018-07-29"
query <-"delete from table tab_name where date <= "
dbSendQuery(conn,paste0( query,"'",a,"'"))
The error I am getting is:
Error in .local(conn, statement, ...) :
could not run statement:
Any hints?
Suppose you're trying to do a typical insert-or-update loop with RSQLite. I would expect the following to work:
library(DBI)
testdb <- dbConnect(RSQLite::SQLite(), "test.sqlite")
dbExecute(testdb, "CREATE TABLE spray_count (spray TEXT, count INTEGER)")
urs <- dbSendStatement(testdb, "UPDATE spray_count SET count = count + :count WHERE spray = :spray")
irs <- dbSendStatement(testdb, "INSERT INTO spray_count VALUES (:spray, :count)")
for (i in 1:nrow(InsectSprays)) {
print(paste("update", i))
dbBind(urs, InsectSprays[i,])
if (!dbGetRowsAffected(urs)) {
print(paste("insert", i))
dbBind(irs, InsectSprays[i,])
}
}
But it does not:
[1] "update 1"
Error in rsqlite_bind_rows(res#ptr, params) :
external pointer is not valid
In addition: Warning message:
Closing open result set, pending rows
Basically it seems that you can have only one prepared statement at a time, and creating a second one somehow invalidates the first. Am I missing something or is this a limitation of DBI and/or RSQLite? I have DBI v0.6-1 and RSQLite v1.1-2.
I'm trying to get to make a query from R to a MySQL database. The query iterates over a list, and therefore changes dynamically. Each query based on each element in the list will also in general result in multiple rows being extract. The database I'm using can be downloaded from here: http://www.ghtorrent.org/msr14.html
In the end of the day all the results should end up in the same output, and look like this:
pull_req_id,user,action,created_at
12359,arthurnn,opened,1380126837
12359,rafaelfranca,discussed,1380127245
12359,arthurnn,discussed,1380127676
...
The code that I have now looks like this, but it's not working:
library(DBI)
library(RMySQL)
m <- dbDriver("MySQL");
con <- dbConnect(m, user='msr14', password='msr14', host='localhost', dbname='msr14');
all_rails_projects <- dbGetQuery(con, 'SELECT * FROM projects WHERE name = "rails";')
all_rails_prs <- dbGetQuery(con, 'SELECT id FROM pull_requests WHERE base_repo_id = 78852;')
out <- nrow(all_rails_prs)
names(out) <- as.list(all_rails_prs)
df <- c('pull_req_id', 'user', 'action', 'created_at')
out <- numeric(length(df))
names(out) <- df
for (i in nrow(all_rails_prs)) {
SQL <- paste("select user, action, created_at from
(
select prh.action as action, prh.created_at as created_at, u.login as user
from pull_request_history prh, users u
where prh.pull_request_id ='", all_rails_prs[i,], "'",
" and prh.actor_id = u.id
union
select ie.action as action, ie.created_at as created_at, u.login as user
from issues i, issue_events ie, users u
where ie.issue_id = i.id
and i.pull_request_id ='", all_rails_prs[i,], "'",
" and ie.actor_id = u.id
union
select 'discussed' as action, ic.created_at as created_at, u.login as user
from issues i, issue_comments ic, users u
where ic.issue_id = i.id
and u.id = ic.user_id
and i.pull_request_id ='", all_rails_prs[i,], "'",
"union
select 'reviewed' as action, prc.created_at as created_at, u.login as user
from pull_request_comments prc, users u
where prc.user_id = u.id
and prc.pull_request_id ='", all_rails_prs[i,], "'",
") as actions
order by created_at;", sep = "")
res <- dbGetQuery(con, SQL)
out[i] <- dbFetch(res, n = -1)
}
This generates the following error message:
Error in (function (classes, fdef, mtable) :
unable to find an inherited method for function ‘dbFetch’ for signature ‘"data.frame"’
In addition: Warning message:
In mysqlExecStatement(conn, statement, ...) :
RS-DBI driver warning: (unrecognized MySQL field type 7 in column 2 imported as character)
I've tried different variants, but they all result in some kind of error, so it seems as if I'm simply not setting up the query structure the right way. Anyone has any advice?
According to the docs, dbGetQuery calls fetch by default if the query is successful.
res is already a database and you can put it into out directly without having to fetch the records.
Also, if you want to store the results in a dataframe and not a list, you might want to try:
#get the results
res<-dbGetQuery(con, SQL)
#if it's not null, add the request id and rbind it to the out dataframe
if(!is.null(res)){
out<-rbind(out,cbind(rep(all_rails_prs[i,],nrow(res)),res))
}
There might also be an error in your for syntax, you might need for (i in 1:nrow(all_rails_prs))