test: Test for quoting columns with dbQuoteIdentifier()

[dpprdan]

This allows quoting columns with Id() and dbQuoteIdentifier() and fixes the quoting of a schema, closes #254.

I've added tests for dbQuoteIdentifier() and dbUnquoteIdentifier() from RPostgres, too.

library(RMariaDB)
con <- mariadbDefault()

# quote column
column_id <- Id(schema = "myschema", table = "mytable", column = "mycolumn")
dbQuoteIdentifier(con, column_id)
#> <SQL> `myschema`.`mytable`.`mycolumn`

# quote schema without dot
(schema_id <- dbQuoteIdentifier(con, Id(schema = "myschema")))
#> <SQL> `myschema`

# glue_sql() example: https://glue.tidyverse.org/reference/glue_sql.html
library(glue)
iris2 <- iris
colnames(iris2) <- gsub("[.]", "_", tolower(colnames(iris)))
DBI::dbWriteTable(con, "iris", iris2)

iris_db <- "iris"
nicknames_db <- "nicknames"

nicknames <- data.frame(
  species = c("setosa", "versicolor", "virginica"),
  nickname = c("Beachhead Iris", "Harlequin Blueflag", "Virginia Iris"),
  stringsAsFactors = FALSE
)

DBI::dbWriteTable(con, nicknames_db, nicknames)

cols <- list(
  DBI::Id(table = iris_db, column = "sepal_length"),
  DBI::Id(table = iris_db, column = "sepal_width"),
  DBI::Id(table = nicknames_db, column = "nickname")
)

iris_species <- DBI::Id(table = iris_db, column = "species")
nicknames_species <- DBI::Id(table = nicknames_db, column = "species")

query <- glue_sql("
  SELECT {`cols`*}
  FROM {`iris_db`}
  JOIN {`nicknames_db`}
  ON {`iris_species`}={`nicknames_species`}",
  .con = con
)
query
#> <SQL> SELECT `iris`.`sepal_length`, `iris`.`sepal_width`, `nicknames`.`nickname`
#> FROM `iris`
#> JOIN `nicknames`
#> ON `iris`.`species`=`nicknames`.`species`

DBI::dbGetQuery(con, query, n = 5)
#>   sepal_length sepal_width       nickname
#> 1          5.1         3.5 Beachhead Iris
#> 2          4.9         3.0 Beachhead Iris
#> 3          4.7         3.2 Beachhead Iris
#> 4          4.6         3.1 Beachhead Iris
#> 5          5.0         3.6 Beachhead Iris

dbExecute(con, glue_sql("DROP TABLE {`nicknames_db`}, iris", .con = con))
#> [1] 0

dbDisconnect(con)

[dpprdan]

I noticed that a table t1 was left behind in the database, so I added temporary = TRUE to two dbWriteTable() tests.

[dpprdan]

Let's make r-dbi/RPostgres#372 work first.

Note that the list_objects_features test (in DBItest) is skipped in RMariaDB, which is why tests are passing here. I.e. I think we should not skip it here, but we might have to modify it, so that it tests better what we want it to test.

RMariaDB/tests/testthat/helper-DBItest.R

Lines 20 to 21 in 0e17617

	# Fails on Ubuntu 18.04:
	"list_objects_features",

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[krlmlr]

Again, implemented independently, but the tests are fine. Thanks!

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This pull request failed to merge: PR cannot be automatically rebased, please rebase manually to continue. Once the issues are resolved, remove the blocked label and re-queue the pull request. Note that the pull request will be automatically re-queued if it has the mergequeue label.

Additional debug info: Failed to rebase this PR onto the latest changes from the base branch. You will probably need to rebase this PR manually and resolve conflicts).

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This pull request failed to merge: PR cannot be automatically rebased, please rebase manually to continue. Once the issues are resolved, remove the blocked label and re-queue the pull request. Note that the pull request will be automatically re-queued if it has the mergequeue label.

Additional debug info: Failed to rebase this PR onto the latest changes from the base branch. You will probably need to rebase this PR manually and resolve conflicts).

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This pull request failed to merge: some CI status(es) failed. Once the issues are resolved, remove the blocked label and re-queue the pull request. Note that the pull request will be automatically re-queued if it has the mergequeue label.

Failed CI(s): Smoke test: stock R