Use `requireNamespace("pkg", quietly = TRUE)` for RMySQL and RSQLite …

…in the examples/tests since these are "Suggests" packages (i.e. not "Depends")

R/DBI-connection-transaction.R

@@ -106,40 +106,45 @@ setMethod("dbWithTransaction", "Pool", function(conn, code) {
 #' @return \code{func}'s return value.
 #' @export
 #' @examples
-#' pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
+#' if (requireNamespace("RSQLite", quietly = TRUE)) {
+#'   pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
 #'
-#' dbWriteTable(pool, "cars", head(cars, 3))
-#' dbReadTable(pool, "cars")   # there are 3 rows
+#'   dbWriteTable(pool, "cars", head(cars, 3))
+#'   dbReadTable(pool, "cars")   # there are 3 rows
 #'
-#' ## successful transaction
-#' poolWithTransaction(pool, function(conn) {
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (1, 1);")
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (2, 2);")
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (3, 3);")
-#' })
-#' dbReadTable(pool, "cars")   # there are now 6 rows
-#'
-#' ## failed transaction -- note the missing comma
-#' tryCatch(
+#'   ## successful transaction
+#'   poolWithTransaction(pool, function(conn) {
+#'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (1, 1);")
+#'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (2, 2);")
+#'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (3, 3);")
+#'   })
+#'   dbReadTable(pool, "cars")   # there are now 6 rows
+#'
+#'   ## failed transaction -- note the missing comma
+#'   tryCatch(
+#'     poolWithTransaction(pool, function(conn) {
+#'       dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (1, 1);")
+#'       dbExecute(conn, "INSERT INTO cars (speed dist) VALUES (2, 2);")
+#'       dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (3, 3);")
+#'     }),
+#'     error = identity
+#'   )
+#'   dbReadTable(pool, "cars")   # still 6 rows
+#'
+#'   ## early exit, silently
 #'   poolWithTransaction(pool, function(conn) {
 #'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (1, 1);")
-#'     dbExecute(conn, "INSERT INTO cars (speed dist) VALUES (2, 2);")
+#'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (2, 2);")
+#'     if (nrow(dbReadTable(conn, "cars")) > 7) dbBreak()
 #'     dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (3, 3);")
-#'   }),
-#'   error = identity
-#' )
-#' dbReadTable(pool, "cars")   # still 6 rows
-#'
-#' ## early exit, silently
-#' poolWithTransaction(pool, function(conn) {
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (1, 1);")
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (2, 2);")
-#'   if (nrow(dbReadTable(conn, "cars")) > 7) dbBreak()
-#'   dbExecute(conn, "INSERT INTO cars (speed, dist) VALUES (3, 3);")
-#' })
-#' dbReadTable(pool, "cars")   # still 6 rows
-#'
-#' poolClose(pool)
+#'   })
+#'   dbReadTable(pool, "cars")   # still 6 rows
+#'
+#'   poolClose(pool)
+#'
+#' } else {
+#'   message("Please install the 'RSQLite' package to run this example")
+#' }
 poolWithTransaction <- function(pool, func) {
   conn <- poolCheckout(pool)
   on.exit(poolReturn(conn))

R/DBI-connection.R

@@ -20,48 +20,53 @@ NULL
 #'
 #' @name DBI-connection
 #' @examples
-#' mtcars1 <- mtcars[ c(1:16), ] # first half of the mtcars dataset
-#' mtcars2 <- mtcars[-c(1:16), ] # second half of the mtcars dataset
+#' if (requireNamespace("RSQLite", quietly = TRUE)) {
+#'   mtcars1 <- mtcars[ c(1:16), ] # first half of the mtcars dataset
+#'   mtcars2 <- mtcars[-c(1:16), ] # second half of the mtcars dataset
 #'
-#' pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
+#'   pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
 #'
-#' # write the mtcars1 table into the database
-#' dbWriteTable(pool, "mtcars", mtcars1, row.names = TRUE)
+#'   # write the mtcars1 table into the database
+#'   dbWriteTable(pool, "mtcars", mtcars1, row.names = TRUE)
 #'
-#' # list the current tables in the database
-#' dbListTables(pool)
+#'   # list the current tables in the database
+#'   dbListTables(pool)
 #'
-#' # read the "mtcars" table from the database (only 16 rows)
-#' dbReadTable(pool, "mtcars")
+#'   # read the "mtcars" table from the database (only 16 rows)
+#'   dbReadTable(pool, "mtcars")
 #'
-#' # append mtcars2 to the "mtcars" table already in the database
-#' dbWriteTable(pool, "mtcars", mtcars2, row.names = TRUE, append = TRUE)
+#'   # append mtcars2 to the "mtcars" table already in the database
+#'   dbWriteTable(pool, "mtcars", mtcars2, row.names = TRUE, append = TRUE)
 #'
-#' # read the "mtcars" table from the database (all 32 rows)
-#' dbReadTable(pool, "mtcars")
+#'   # read the "mtcars" table from the database (all 32 rows)
+#'   dbReadTable(pool, "mtcars")
 #'
-#' # get the names of the columns in the databases's table
-#' dbListFields(pool, "mtcars")
+#'   # get the names of the columns in the databases's table
+#'   dbListFields(pool, "mtcars")
 #'
-#' # use dbExecute to change the "mpg" and "cyl" values of the 1st row
-#' dbExecute(pool,
-#'   paste(
-#'     "UPDATE mtcars",
-#'     "SET mpg = '22.0', cyl = '10'",
-#'     "WHERE row_names = 'Mazda RX4'"
+#'   # use dbExecute to change the "mpg" and "cyl" values of the 1st row
+#'   dbExecute(pool,
+#'     paste(
+#'       "UPDATE mtcars",
+#'       "SET mpg = '22.0', cyl = '10'",
+#'       "WHERE row_names = 'Mazda RX4'"
+#'     )
 #'   )
-#' )
 #'
-#' # read the 1st row of "mtcars" table to confirm the previous change
-#' dbGetQuery(pool, "SELECT * FROM mtcars WHERE row_names = 'Mazda RX4'")
+#'   # read the 1st row of "mtcars" table to confirm the previous change
+#'   dbGetQuery(pool, "SELECT * FROM mtcars WHERE row_names = 'Mazda RX4'")
 #'
-#' # drop the "mtcars" table from the database
-#' dbRemoveTable(pool, "mtcars")
+#'   # drop the "mtcars" table from the database
+#'   dbRemoveTable(pool, "mtcars")
 #'
-#' # list the current tables in the database
-#' dbListTables(pool)
+#'   # list the current tables in the database
+#'   dbListTables(pool)
 #'
-#' poolClose(pool)
+#'   poolClose(pool)
+#'
+#' } else {
+#'   message("Please install the 'RSQLite' package to run this example")
+#' }
 NULL
 
 ## Throw error here since this would require keeping a connection

R/DBI-object.R

@@ -10,25 +10,30 @@ NULL
 #'
 #' @name DBI-object
 #' @examples
-#' pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
+#' if (requireNamespace("RSQLite", quietly = TRUE)) {
+#'   pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
 #'
-#' dbGetInfo(pool)
-#' dbIsValid(pool)
+#'   dbGetInfo(pool)
+#'   dbIsValid(pool)
 #'
-#' dbDataType(pool, 1:5)
-#' dbDataType(pool, 1)
-#' dbDataType(pool, TRUE)
-#' dbDataType(pool, Sys.Date())
-#' dbDataType(pool, Sys.time())
-#' dbDataType(pool, Sys.time() - as.POSIXct(Sys.Date()))
-#' dbDataType(pool, c("x", "abc"))
-#' dbDataType(pool, list(raw(10), raw(20)))
-#' dbDataType(pool, I(3))
-#' dbDataType(pool, iris)
+#'   dbDataType(pool, 1:5)
+#'   dbDataType(pool, 1)
+#'   dbDataType(pool, TRUE)
+#'   dbDataType(pool, Sys.Date())
+#'   dbDataType(pool, Sys.time())
+#'   dbDataType(pool, Sys.time() - as.POSIXct(Sys.Date()))
+#'   dbDataType(pool, c("x", "abc"))
+#'   dbDataType(pool, list(raw(10), raw(20)))
+#'   dbDataType(pool, I(3))
+#'   dbDataType(pool, iris)
 #'
-#' poolClose(pool)
+#'   poolClose(pool)
 #'
-#' dbIsValid(pool)
+#'   dbIsValid(pool)
+#'
+#' } else {
+#'   message("Please install the 'RSQLite' package to run this example")
+#' }
 NULL
 
 #' @param dbObj,obj,... See \code{\link[DBI]{dbDataType}}.

R/DBI.R

@@ -38,23 +38,28 @@ NULL
 #'
 #' @export
 #' @examples
-#' pool <- dbPool(
-#'   drv = RMySQL::MySQL(),
-#'   dbname = "shinydemo",
-#'   host = "shiny-demo.csa7qlmguqrf.us-east-1.rds.amazonaws.com",
-#'   username = "guest",
-#'   password = "guest"
-#' )
+#' if (requireNamespace("RMySQL", quietly = TRUE)) {
+#'   pool <- dbPool(
+#'     drv = RMySQL::MySQL(),
+#'     dbname = "shinydemo",
+#'     host = "shiny-demo.csa7qlmguqrf.us-east-1.rds.amazonaws.com",
+#'     username = "guest",
+#'     password = "guest"
+#'   )
 #'
-#' dbGetQuery(pool, "SELECT * from City LIMIT 5;")
-#' #>   ID           Name CountryCode      District Population
-#' #> 1  1          Kabul         AFG         Kabol    1780000
-#' #> 2  2       Qandahar         AFG      Qandahar     237500
-#' #> 3  3          Herat         AFG         Herat     186800
-#' #> 4  4 Mazar-e-Sharif         AFG         Balkh     127800
-#' #> 5  5      Amsterdam         NLD Noord-Holland     731200
+#'   dbGetQuery(pool, "SELECT * from City LIMIT 5;")
+#'   #>   ID           Name CountryCode      District Population
+#'   #> 1  1          Kabul         AFG         Kabol    1780000
+#'   #> 2  2       Qandahar         AFG      Qandahar     237500
+#'   #> 3  3          Herat         AFG         Herat     186800
+#'   #> 4  4 Mazar-e-Sharif         AFG         Balkh     127800
+#'   #> 5  5      Amsterdam         NLD Noord-Holland     731200
 #'
-#' poolClose(pool)
+#'   poolClose(pool)
+#'
+#' } else {
+#'   message("Please install the 'RMySQL' package to run this example")
+#' }
 dbPool <- function(drv, ..., validateQuery = NULL) {
   state <- new.env(parent = emptyenv())
   state$validateQuery <- validateQuery

R/dbplyr.R

@@ -14,38 +14,43 @@ NULL
 #' @name dplyr-db-methods
 #'
 #' @examples
-#' library(dplyr)
+#' if (requireNamespace("RSQLite", quietly = TRUE)) {
+#'   library(dplyr)
 #'
-#' pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
+#'   pool <- dbPool(RSQLite::SQLite(), dbname = ":memory:")
 #'
-#' # describe the type of the pool/its connections
-#' db_desc(pool)
+#'   # describe the type of the pool/its connections
+#'   db_desc(pool)
 #'
-#' # use dplyr syntax to copy a table into the database
-#' copy_to(pool, mtcars, "mtcars", temporary = FALSE)
+#'   # use dplyr syntax to copy a table into the database
+#'   copy_to(pool, mtcars, "mtcars", temporary = FALSE)
 #'
-#' # list the current tables in the database
-#' db_list_tables(pool)
+#'   # list the current tables in the database
+#'   db_list_tables(pool)
 #'
-#' # extract a table from the database
-#' mtcars_db <- tbl(pool, "mtcars")
+#'   # extract a table from the database
+#'   mtcars_db <- tbl(pool, "mtcars")
 #'
-#' # select only 3 columns
-#' mtcars_db_thin <- select(mtcars_db, mpg, cyl, disp)
+#'   # select only 3 columns
+#'   mtcars_db_thin <- select(mtcars_db, mpg, cyl, disp)
 #'
-#' # get the names of the columns in the databases's table
-#' db_query_fields(pool, "mtcars")
+#'   # get the names of the columns in the databases's table
+#'   db_query_fields(pool, "mtcars")
 #'
-#' # get the number of rows in the databases's table
-#' db_query_rows(pool, "mtcars")
+#'   # get the number of rows in the databases's table
+#'   db_query_rows(pool, "mtcars")
 #'
-#' # drop the "mtcars" table from the database
-#' db_drop_table(pool, "mtcars")
+#'   # drop the "mtcars" table from the database
+#'   db_drop_table(pool, "mtcars")
 #'
-#' # list the current tables in the database
-#' db_list_tables(pool)
+#'   # list the current tables in the database
+#'   db_list_tables(pool)
 #'
-#' poolClose(pool)
+#'   poolClose(pool)
+#'
+#' } else {
+#'   message("Please install the 'RSQLite' package to run this example")
+#' }
 NULL
 
 stopIfTemporary <- function(temporary) {