transmute does not work with DBI

[danielmcauley]

transmute() exhibits desired behavior with data frames but throws an error when used in the context of a DBI.

# this runs

library(dplyr)

transmute(mtcars, blah = cyl)

# this does not

library(dbplyr)

con <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
copy_to(con, mtcars)
mtcars2 <- tbl(con, "mtcars")
transmute(mtcars2, blah = cyl)

# Error: Variable context not set

[edgararuiz-zz]

Hi, I just tried that out and it worked in my computer:

suppressPackageStartupMessages({                    
library(dplyr)                                      
library(dbplyr)                                     
})                                                  
con <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
copy_to(con, mtcars)                                
mtcars2 <- tbl(con, "mtcars")                       
transmute(mtcars2, blah = cyl)                      
#> # Source:   lazy query [?? x 1]
#> # Database: sqlite 3.19.3 [:memory:]
#>     blah
#>    <dbl>
#>  1  6.00
#>  2  6.00
#>  3  4.00
#>  4  6.00
#>  5  8.00
#>  6  6.00
#>  7  8.00
#>  8  4.00
#>  9  4.00
#> 10  6.00
#> # ... with more rows
DBI::dbDisconnect(con)                              

Maybe you may need to upgrade your packages?

[danielmcauley]

Thanks, @edgararuiz. I'm on dplyr 0.7.4 and dbplyr 1.2.1 so I don't think those should be the issue. Here's my session info in case there's something I'm missing.

> sessionInfo()
R version 3.4.0 (2017-04-21)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS  10.13.3

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] dbplyr_1.2.1  dplyr_0.7.4

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.15     digest_0.6.9     assertthat_0.2.1 R6_2.2.2        
 [5] DBI_0.7          magrittr_1.5     RSQLite_2.0      pillar_1.1.0    
 [9] rlang_0.1.6      blob_1.1.0       bindrcpp_0.2     tools_3.4.0     
[13] bit64_0.9-7      glue_1.2.0       purrr_0.2.4      bit_1.1-12      
[17] yaml_2.1.13      compiler_3.4.0   pkgconfig_2.0.1  memoise_1.0.0   
[21] tidyselect_0.2.3 bindr_0.1        tibble_1.4.2

[krlmlr]

Can you please try updating tidyselect ?

[lionel-]

dbplyr now uses tidyselect and it looks like tidyselect doesn't hotpatch dplyr for some reason. This problem should go away once the next version of dplyr comes out.

[krlmlr]

Thanks. I don't understand "hotpatch".

[lionel-]

This ugly thing here :) https://github.com/tidyverse/tidyselect/blob/master/R/tidyselect.R#L9

Necessary because tidyr uses tidyselect but not dplyr (and now dbplyr uses it as well).

[krlmlr]

I still don't understand, tidyr does import dplyr even in v0.8.0.

[lionel-]

yes but since tidyr uses tidyselect the variable context from the select helpers (which are exported from dplyr) must be the one from tidyselect.

[danielmcauley]

@krlmlr I updated tidyselect as you suggested but I am still getting the same error. These are the versions I'm currently running: tidyselect_0.2.4 dbplyr_1.2.1 dplyr_0.7.4

[krlmlr]

@lionel-: Do you think reinstalling dplyr can help?

[lionel-]

I don't know what's going on. If you install the dev version it should work though.

[lock]

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