dbplyr

问题 I'm trying to figure out how to a query to generate an ARRAY given a sliding window over a character column with Postgre. For example, if I have this: pid <chr> 1 WP_096038768.1 2 WP_013465871.1 3 WP_058155244.1 4 WP_011329269.1 5 WP_058374608.1 6 WP_089368983.1 7 WP_096739105.1 8 WP_089346667.1 9 WP_096041177.1 10 WP_010553306.1 ... I want a sliding window of size 1 before and after the row. The result is this: pid g <chr> <chr> 1 WP_013465871.1 WP_096038768.1,WP_013465871.1,WP_058155244.1 2

问题 I would like to calculate the Jaro-Winkler string distance in a database. If I bring the data into R (with collect ) I can easily use the stringdist function from the stringdist package. But my data is very large and I'd like to filter on Jaro-Winkler distances before pulling the data into R. There is SQL code for Jaro-Winkler (https://androidaddicted.wordpress.com/2010/06/01/jaro-winkler-sql-code/ and a version for T-SQL) but I guess I'm not sure how best to get that SQL code to work with

问题 I would like to calculate the Jaro-Winkler string distance in a database. If I bring the data into R (with collect ) I can easily use the stringdist function from the stringdist package. But my data is very large and I'd like to filter on Jaro-Winkler distances before pulling the data into R. There is SQL code for Jaro-Winkler (https://androidaddicted.wordpress.com/2010/06/01/jaro-winkler-sql-code/ and a version for T-SQL) but I guess I'm not sure how best to get that SQL code to work with

问题 I'm trying to filter a data frame with user input as radio buttons. Unfortunately, only one type of filter works (the "Annual" version in my example), but the "Monthly" and "Quarterly" options are not returning anything. Here is my sample data set and code. # sample data mydf <- data.frame("Data"=rnorm(12), "Months"=c("Jan", "Nov", "Dec", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct")) library(shiny) library(dbplyr) ui <- fluidPage( # Input() function radioButtons(inputId =

问题 I'm using dplyr (0.7.0) , dbplyr (1.0.0) , DBI 0.6-1 , and odbc (1.0.1.9000) . I would like to do something like the following: db1 <- DBI::dbConnect( odbc::odbc(), Driver = "SQL Server", Server = "MyServer", Database = "DB1" ) db2 <- DBI::dbConnect( odbc::odbc(), Driver = "SQL Server", Server = "MyServer", Database = "DB2" ) x <- tbl(db1, "Table1") %>% dplyr::left_join(tbl(db2, "Table2"), by = "JoinColumn") but I keep getting an error that doesn't really seem to have any substance to it.

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 I can connect to my Sybase IQ 16 database using a connection string such as: myDB_conn <- dbConnect(odbc(), "MyDSN_Name") When I run this command the connections view shows a list of databases and corresponding tables/views. However when I try to use the logic laid out here specifically naming the view I keep receiving an error about my view not being found. test <- tbl(myDB_conn, "OFFSHORE_BOB.SOME_VIEW_OR_TABLE_NAME") In the connection window I can see the database and view but when I use

问题 This question arises because I wish to make a function for my convenience: as.numeric_psql <- function(x) { return(as.numeric(as.integer(x))) } to convert boolean values in a remote postgres table into numeric. The step to convert to integer is needed as: There is no direct cast defined between numeric and boolean. You can use integer as middle-ground. (https://stackoverflow.com/a/19290671/2109289) Of course this function works as expected locally: copy_to(con_psql, cars, 'tmp_cars') tmp_cars

问题 Say you have your tables stores in an SQL server DB, and you want to perform multi table actions, i.e. join several tables from that same database. Following code can interact and receive data from SQL server: library(dplyr) library(odbc) con <- dbConnect(odbc::odbc(), .connection_string = "Driver={SQL Server};Server=.;Database=My_DB;") Table1 <- tbl(con, "Table1") Table1 # View glimpse of Table1 Table2 <- tbl(con, "Table2") Table2 # View glimpse of Table2 Table3 <- tbl(con, "Table3") However