Nothing
#' spec_meta_get_row_count
#' @family meta specifications
#' @usage NULL
#' @format NULL
#' @keywords NULL
spec_meta_get_row_count <- list(
get_row_count_formals = function() {
# <establish formals of described functions>
expect_equal(names(formals(dbGetRowCount)), c("res", "..."))
},
row_count_query = function(con) {
#' @return
#' `dbGetRowCount()` returns a scalar number (integer or numeric),
#' the number of rows fetched so far.
query <- trivial_query()
#' After calling [dbSendQuery()],
res <- local_result(dbSendQuery(con, query))
rc <- dbGetRowCount(res)
#' the row count is initially zero.
expect_equal(rc, 0L)
#' After a call to [dbFetch()] without limit,
check_df(dbFetch(res))
rc <- dbGetRowCount(res)
#' the row count matches the total number of rows returned.
expect_equal(rc, 1L)
},
#
row_count_query_limited = function(ctx, con) {
query <- sql_union(.ctx = ctx, trivial_query(), "SELECT 2", "SELECT 3")
res <- local_result(dbSendQuery(con, query))
rc1 <- dbGetRowCount(res)
expect_equal(rc1, 0L)
#' Fetching a limited number of rows
check_df(dbFetch(res, 2L))
#' increases the number of rows by the number of rows returned,
rc2 <- dbGetRowCount(res)
expect_equal(rc2, 2L)
#' even if fetching past the end of the result set.
check_df(dbFetch(res, 2L))
rc3 <- dbGetRowCount(res)
expect_equal(rc3, 3L)
},
#
row_count_query_empty = function(ctx, con) {
#' For queries with an empty result set,
query <- sql_union(
.ctx = ctx, "SELECT * FROM (SELECT 1 as a) a WHERE (0 = 1)"
)
res <- local_result(dbSendQuery(con, query))
rc <- dbGetRowCount(res)
#' zero is returned
expect_equal(rc, 0L)
check_df(dbFetch(res))
rc <- dbGetRowCount(res)
#' even after fetching.
expect_equal(rc, 0L)
},
#
row_count_statement = function(con, table_name) {
query <- paste0("CREATE TABLE ", table_name, " (a integer)")
#' For data manipulation statements issued with
#' [dbSendStatement()],
res <- local_result(dbSendStatement(con, query))
rc <- dbGetRowCount(res)
#' zero is returned before
expect_equal(rc, 0L)
expect_warning(check_df(dbFetch(res)))
rc <- dbGetRowCount(res)
#' and after calling `dbFetch()`.
expect_equal(rc, 0L)
},
#'
get_row_count_error = function(con) {
#' @section Failure modes:
res <- dbSendQuery(con, trivial_query())
dbClearResult(res)
#' Attempting to get the row count for a result set cleared with
#' [dbClearResult()] gives an error.
expect_error(dbGetRowCount(res))
},
#
NULL
)
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