dbplyr 2.4.0 - connecting to a table via a database link no longer works

[mgarbuzov]

This connection still works in 2.3.4, doesn't work since 2.4.0.

tbl(con, from = in_schema("MY_SCHEMA", sql("MY_TABLE@MY_DB_LINK")))

Error in `db_query_fields.DBIConnection()`:
! Can't query fields.
Caused by error:
! nanodbc/nanodbc.cpp:1710: 42S02
[Oracle][ODBC][Ora]ORA-00942: table or view does not exist
 
Run `rlang::last_trace()` to see where the error occurred.
> rlang::last_trace()
<error/rlang_error>
Error in `db_query_fields.DBIConnection()`:
! Can't query fields.
Caused by error:
! nanodbc/nanodbc.cpp:1710: 42S02
[Oracle][ODBC][Ora]ORA-00942: table or view does not exist
 
---
Backtrace:
     ▆
  1. ├─dplyr::tbl(con, from = in_schema("MY_SCHEMA", sql("MY_TABLE@MY_DB_LINK")))
  2. └─dplyr:::tbl.DBIConnection(con, from = in_schema("MY_SCHEMA", sql("MY_TABLE@MY_DB_LINK")))
  3.   ├─dplyr::tbl(...)
  4.   └─dbplyr:::tbl.src_dbi(...)
  5.     └─dbplyr::tbl_sql(c(subclass, "dbi"), src = src, from = from, ...)
  6.       ├─vars %||% dbplyr_query_fields(src$con, from)
  7.       └─dbplyr:::dbplyr_query_fields(src$con, from)
  8.         └─dbplyr:::dbplyr_fallback(con, "db_query_fields", ...)
  9.           ├─rlang::eval_bare(expr((!!fun)(con, ...)))
 10.           └─dbplyr:::db_query_fields.DBIConnection(con, ...)
Run rlang::last_trace(drop = FALSE) to see 6 hidden frames.

[hadley]

What is a database link?

[mgarbuzov]

@hadley if you have two databases, you can set up a link between them. Then, when you're connected to Database A, you can query tables in Database B via the link by including table_name@link_name (see here). The problem is, I was able to do this in dbplyr 2.3.4 by wrapping the table name with the link in sql(), but it stopped working since 2.4.0.

Upd: not sure, but might be related to Issue #1388 since their query also wrapped table name in dbplyr::sql().

[hadley]

Yeah, looks like a duplicate of #1388, which I'm working on now.