Can't access existing MonetDB with dplyr

Question

I created a MonetDBLite database yesterday, populated it, and was accessing it with dplyr, however this morning I don't seem able to use dplyr.

Here's my connection:

statcast_db <- MonetDBLite::src_monetdblite("/Users/williampetti/statcast_database/statcast_db_Monet", create = FALSE)

And here's a simple query for the statcast_17 table:

statcast_db %>% 
    tbl("statcast_17") %>% 
    select(game_date) %>% 
    distinct() %>% 
    collect() %>% 
    tail(n = 1)

Yesterday, this worked fine. This morning, I get this error:

Error in UseMethod("db_query_fields") : 
  no applicable method for 'db_query_fields' applied to an object of class "MonetDBEmbeddedConnection"

If I use a simple dbGetQuery call, however, it works fine:

> dbGetQuery(statcast_db$con, "SELECT game_date FROM statcast_17 ORDER BY game_date DESC LIMIT 1")
   game_date
1 2017-04-29

Here's my session info:

> sessionInfo()
R version 3.3.1 (2016-06-21)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.6 (El Capitan)

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] xml2_1.1.1        baseballr_0.3.1   RSQLite_1.0.0     pacman_0.4.1     
 [5] dplyr_0.5.0       purrr_0.2.2       readr_1.0.0       tidyr_0.6.0      
 [9] tibble_1.2        ggplot2_2.2.1     tidyverse_1.0.0   magrittr_1.5     
[13] MonetDBLite_0.3.1 RMySQL_0.10.9     DBI_0.5-1        

loaded via a namespace (and not attached):
 [1] splines_3.3.1       lattice_0.20-33     colorspace_1.2-6   
 [4] htmltools_0.3.5     mgcv_1.8-12         chron_2.3-47       
 [7] XML_3.98-1.6        survival_2.40-1     hexbin_1.27.1      
[10] foreign_0.8-66      RColorBrewer_1.1-2  plyr_1.8.4         
[13] stringr_1.2.0       munsell_0.4.3       gtable_0.2.0       
[16] rvest_0.3.2         XML2R_0.0.6         codetools_0.2-14   
[19] latticeExtra_0.6-28 knitr_1.14          reldist_1.6-6      
[22] htmlTable_1.7       Rcpp_0.12.9         acepack_1.4.1      
[25] scales_0.4.1        pitchRx_1.8.2       Hmisc_4.0-0        
[28] gridExtra_2.2.1     digest_0.6.11       stringi_1.1.3      
[31] grid_3.3.1          tools_3.3.1         bitops_1.0-6       
[34] lazyeval_0.2.0      RCurl_1.95-4.8      Formula_1.2-1      
[37] cluster_2.0.4       MASS_7.3-45         Matrix_1.2-6       
[40] data.table_1.9.6    lubridate_1.6.0     httr_1.2.1         
[43] assertthat_0.1      R6_2.1.3            rpart_4.1-10       
[46] nnet_7.3-12         nlme_3.1-128

Please try with the dev version of MonetDBLite from Github. Dplyr recently made some changes. — Hannes Mühleisen, May 01 '17 at 13:22
When I try to install the dev version I get this `Error: Could not find build tools necessary to build MonetDBLite`. Other dev versions of packages install fine for me with `devtools::install_github`. — BillPetti, May 01 '17 at 13:48
You might need to install xcode command line tools on OSX for this since MonetDBLite contains lots of C code — Hannes Mühleisen, May 01 '17 at 14:24
Still running into the same problem. Updated to dev version of `MoneyDBLite`, as well as `dbplyr` and `dplyr`. Also now running `R` 3.4. — BillPetti, May 01 '17 at 16:40
Could you perhaps make a simple reproducible example with the mtcars table please? I'd like to turn this into a test case. — Hannes Mühleisen, May 03 '17 at 07:08
Still no luck with dev versions of DBI, MonetDBLite, dbplyr & dplyr? — Hannes Mühleisen, May 23 '17 at 07:18
No, unfortunately I couldn't get it to work, so used basic SQL query instead of dplyr at this point. — BillPetti, May 23 '17 at 18:12
So, I don't know if this is the issue, but I am attaching packages in this order and it's allowing me to use `dplyr` to query my database: `MonetDBLite`, `DBI`, `tidyverse`. When I switch the order it gives me the same old error. — BillPetti, Apr 06 '18 at 13:38
Yes, although I believe I had the same issue outside of RStudio — BillPetti, Nov 22 '18 at 19:56

score 0 · Answer 1 · answered Nov 14 '18 at 21:45

0

I just replied to a similar question this morning after figuring out that the order in which you load MonetDBLite matters. I came across this question trying to figure out why it does matter. I was having the same type of Error in UseMethod problems as BillPetti. Making sure MonetDBLite loads after dplyr and dbplyr has resolved the issue for me. Here's the link to that other answer:

https://stackoverflow.com/a/53307673/3705612

answered Nov 14 '18 at 21:45

Corey N.

159
11

Just wanted to acknowledge that I hadn't seen @BillPetti's last comment (dated 6-Apr-2018) when offering my answer. And now I'm wondering if it's really the order of package loading that is causing the error or whether instead if it's the pre-existing "src_monetdb" object in the workspace when starting the R session. With a clean workspace I can load MonetDBLite before `dplyr` and `dbplyr` and have it work. – Corey N. Nov 14 '18 at 22:21

Can't access existing MonetDB with dplyr

1 Answers1