r-dbi

问题 I am new to R and new to Stack Overflow, so apologies if I don't post this correctly! I have R linked to an Access database using the ODBC and DBI packages. I scoured the internet and couldn't find a way to write an update query, so I've created a loop that manually pretty much does the same thing. The problem is that to do this, I am using the dbSendStatement function. It seems that when you use that function you need a way to then end it before moving onto another query, or else you get

问题 I have R linked to an Access database using the ODBC and DBI packages. I scoured the internet and couldn't find a way to write an update query, so I'm using the dbSendStatement function to update entries individually. Combined with a for loop, this effectively works like an update query with one snag - when I try to update any field in the database that is text I get an error that says "[Microsoft][ODBC Microsoft Access Driver] One of your parameters is invalid." DBI::dbSendStatement(conn =

问题 I have R linked to an Access database using the ODBC and DBI packages. I scoured the internet and couldn't find a way to write an update query, so I'm using the dbSendStatement function to update entries individually. Combined with a for loop, this effectively works like an update query with one snag - when I try to update any field in the database that is text I get an error that says "[Microsoft][ODBC Microsoft Access Driver] One of your parameters is invalid." DBI::dbSendStatement(conn =

问题 I can use the following code in R to select distinct rows in any generic SQL database. I'd use dplyr::distinct() but it's not supported in SQL syntax. Anyways, this does indeed work: dbGetQuery(database_name, "SELECT t.* FROM (SELECT t.*, ROW_NUMBER() OVER (PARTITION BY column_name ORDER BY column_name) AS SEQNUM FROM table_name t ) t WHERE SEQNUM = 1;") I've been using it with success, but wonder how I can pipe that same SQL query after other dplyr steps, as opposed to just using it as a

问题 I can use the following code in R to select distinct rows in any generic SQL database. I'd use dplyr::distinct() but it's not supported in SQL syntax. Anyways, this does indeed work: dbGetQuery(database_name, "SELECT t.* FROM (SELECT t.*, ROW_NUMBER() OVER (PARTITION BY column_name ORDER BY column_name) AS SEQNUM FROM table_name t ) t WHERE SEQNUM = 1;") I've been using it with success, but wonder how I can pipe that same SQL query after other dplyr steps, as opposed to just using it as a

问题 Here is mtcars data in the MonetDBLite database file. library(MonetDBLite) library(tidyverse) library(DBI) dbdir <- getwd() con <- dbConnect(MonetDBLite::MonetDBLite(), dbdir) dbWriteTable(conn = con, name = "mtcars_1", value = mtcars) data_mt <- con %>% tbl("mtcars_1") I want to use dplyr mutate to create new variables and add (commit!) that to the database table? Something like data_mt %>% select(mpg, cyl) %>% mutate(var = mpg/cyl) %>% dbCommit(con) The desired output should be same when we

问题 I need to update column values conditionnaly on other columns in some PostgreSQL database table. I managed to do it writing an SQL statement in R and executing it with dbExecute from DBI package. library(dplyr) library(DBI) # Establish connection with database con <- dbConnect(RPostgreSQL::PostgreSQL(), dbname = "myDb", host="localhost", port= 5432, user="me",password = myPwd) # Write SQL update statement request <- paste("UPDATE table_to_update", "SET var_to_change = 'new value' ", "WHERE

问题 In R I am running the following query to retrieve data: test <- dbGetQuery(conn = GetConnection("default"), statement = "SELECT PK_FK_RW_BOND_HOLDING_VAL_BOND, PK_CASHFLOW_DAT FROM RW_CASH_FLOWS_ON_BONDS WHERE PK_FK_RW_BOND_HOLDING_VAL_BOND = 'AT0000385745' OR PK_FK_RW_BOND_HOLDING_VAL_BOND = 'RU000A0JV7J9'") This returns PK_FK_RW_BOND_HOLDING_VAL_BOND PK_CASHFLOW_DAT RU000A0JV7J9 2018-01-14 23:00:00 RU000A0JV7J9 2017-01-14 23:00:00 RU000A0JV7J9 2019-08-01 00:00:00 RU000A0JV7J9 2019-01-31 23

问题 From R Studio's ODBC database documentation I can see a simple example of how to read a SQL table into an R data frame: data <- dbReadTable(con, "flights") Let me paste a graphic of the BGBUref table(?) I'm trying to read to an R data frame. This is from my connection pane in R studio. If I use the same syntax as above, where con is the output of my dbConnect(...) I get the following: df <- dbReadTable(con, "BGBURef") #> Error: <SQL> 'SELECT * FROM "BGBURef"' nanodbc/nanodbc.cpp:1587: 42S02:

问题 I've been scouring stackoverflow and google for an hour trying to figure out why my table won't show up. So far solutions that have worked for others, don't work for me. I'm connecting to a database like this: library(DBI) library(dplyr) con <- dbConnect(odbc::odbc(), .connection_string = "Driver={SQL Server};", user = rstudioapi::askForPassword("Your computer usename e.g. SmithJo"), password = rstudioapi::askForPassword("Your computer password (e.g. to login to Windows)"), port = 1433,