in_schema does not work inside compute for remote table

[willshen99]

Package Version:

RPresto: 1.4.7
DBI: 1.2.3
dbplyr: 2.5.0

Issue 1

This is a similar issue to #275
When I ran

dplyr::copy_to(
  conn, 
  some_remote_table,
  name = in_schema('test', 'test_table')
)

I got an error

Error in vapply(x, unclass, character(1)) : values must be length 1,
 but FUN(X[[1]]) result is length 0

The issue comes from the unconditional unname(). Similar issue was also reported in dbplyr tidyverse/dbplyr#938

RPresto/R/dbplyr-src.R

Lines 275 to 276 in 3013b53

	.compute_tbl_presto <- function(x, name, temporary = FALSE, ..., cte = FALSE) {
	name <- unname(name)

Issue 1 Fix

I'm able to fix this by adding a conditional unname()

  if (is_bare_character(x) || dbplyr::is.ident(x) || dbplyr::is.sql(x)) {
    name <- unname(name)

Issue 2

After applying fix above, the compute continues but outputs the table in connection schema, not the schema specified in in_schema.

> dplyr::copy_to(
+   conn, 
+   some_remote_table,
+   name = in_schema('test', 'test_table')
+ )
  query FINISHED [============================================>----]  91% in  3s> 
dbExistsTable(conn, in_schema("test", "test_table"))
[1] FALSE
> dbExistsTable(conn, in_schema("default", "test_table"))
[1] TRUE

Issue 2 Fix

The issue comes from sqlCreateTableAs calls dbplyr_table_path to get target table name. The function dbplyr_table_path returns the last component of the table path (i.e. the name of the table). So the schema name is omitted. I was able to fix it by removing table_path_name call.

RPresto/R/sqlCreateTableAs.R

Lines 34 to 35 in 3013b53

	if (inherits(name, "dbplyr_table_path")) { # dbplyr >= 2.5.0
	name <- dbplyr::table_path_name(name, con)

I'm happy to start a PR.