Implement a dbCreateTable method (#568)

Fixes #483

NEWS.md

@@ -1,10 +1,10 @@
 # bigrquery (development version)
 
+* Now supports `dbAppendTable()` (#539) and `dbCreateTable()` (#483).
+
 * `dbWriteTable()` now correct uses the `billing` value set in the 
   connection (#486).
 
-* Now supports `dbAppendTable()` (#539).
-
 * `dbReadTable()`, `dbWriteTable()`, `dbExistsTable()`, `dbRemoveTable()`,
   and `dbListFields()` now all work with `DBI::Id()` (#537).
 

R/dbi-connection.R

@@ -239,6 +239,30 @@ setMethod("dbAppendTable", c("BigQueryConnection", "character", "data.frame"), d
 #' @export
 setMethod("dbAppendTable", c("BigQueryConnection", "Id", "data.frame"), dbAppendTable_bq)
 
+dbCreateTable_bq <- function(conn,
+                             name,
+                             fields,
+                             ...,
+                             row.names = NULL,
+                             temporary = FALSE) {
+  if (!identical(temporary, FALSE)) {
+    stop("Temporary tables not supported by bigrquery", call. = FALSE)
+  }
+
+  tb <- as_bq_table(conn, name)
+  bq_table_create(tb, fields)
+
+  invisible(TRUE)
+}
+
+#' @inheritParams DBI::dbCreateTable
+#' @rdname DBI
+#' @export
+setMethod("dbCreateTable", "BigQueryConnection", dbCreateTable_bq)
+
+#' @rdname DBI
+#' @export
+setMethod("dbCreateTable", "BigQueryConnection", dbCreateTable_bq)
 
 dbReadTable_bq <- function(conn, name, ...) {
   tb <- as_bq_table(conn, name)

tests/testthat/test-dbi-connection.R

@@ -77,27 +77,30 @@ test_that("can use DBI::Id()", {
   df <- data.frame(x = 1:10)
   id <- DBI::Id(table = "mytable")
 
-  expect_no_error(DBI::dbWriteTable(con, id, df))
+  expect_no_error(DBI::dbCreateTable(con, id, df))
   expect_no_error(DBI::dbAppendTable(con, id, df))
+  expect_no_error(DBI::dbWriteTable(con, id, df, overwrite = TRUE))
   expect_no_error(DBI::dbReadTable(con, id))
   expect_true(DBI::dbExistsTable(con, id))
   expect_no_error(DBI::dbListFields(con, id))
   expect_no_error(DBI::dbRemoveTable(con, id))
 })
 
-test_that("can append to an existing dataset", {
-  ds <- bq_test_dataset()
-  con <- DBI::dbConnect(ds)
+test_that("can create an empty dataset then append to it", {
+  tb <- bq_test_table()
+  con <- DBI::dbConnect(bq_dataset(tb$project, tb$dataset))
 
   df <- data.frame(x = 1, y = 2)
-  DBI::dbWriteTable(con, "df", df)
-  DBI::dbWriteTable(con, "df", df, append = TRUE)
+  DBI::dbCreateTable(con, tb$table, df)
+  expect_equal(bq_table_nrow(tb), 0)
 
-  # Or with dbAppend
-  DBI::dbAppendTable(con, "df", df)
+  # With dbWriteTable
+  DBI::dbWriteTable(con, tb$table, df, append = TRUE)
+  expect_equal(bq_table_nrow(tb), 1)
 
-  df2 <- DBI::dbReadTable(con, "df")
-  expect(nrow(df2), 3L)
+  # Or with dbAppend
+  DBI::dbAppendTable(con, tb$table, df)
+  expect_equal(bq_table_nrow(tb), 2)
 })
 
 test_that("dataset is optional", {