Fixed dbFetch() for DBI drivers, no longer ignoring n argument.

OHDSI · Nov 13, 2023 · 6f680df · 6f680df
1 parent 650f49f
commit 6f680df
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Showing 4 changed files with 20 additions and 3 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: DatabaseConnector
 Type: Package
 Title: Connecting to Various Database Platforms
-Version: 6.3.0
+Version: 6.3.1
 Date: 2023-11-08
 Authors@R: c(
     person("Martijn", "Schuemie", email = "schuemie@ohdsi.org", role = c("aut", "cre")),

diff --git a/NEWS.md b/NEWS.md
@@ -1,3 +1,11 @@
+DatabaseConnector 6.3.1
+=======================
+
+Bugfixes:
+
+1. Fixed `dbFetch()` for DBI drivers, no longer ignoring `n` argument.
+
+
 DatabaseConnector 6.3.0
 =======================
 

diff --git a/R/DBI.R b/R/DBI.R
@@ -376,8 +376,8 @@ setMethod("dbFetch", "DatabaseConnectorJdbcResult", function(res, n = -1, ...) {
 
 #' @inherit DBI::dbFetch title description params details references return seealso
 #' @export
-setMethod("dbFetch", "DatabaseConnectorDbiResult", function(res, ...) {
-  columns <- DBI::dbFetch(res@resultSet, ...)
+setMethod("dbFetch", "DatabaseConnectorDbiResult", function(res, n = -1, ...) {
+  columns <- DBI::dbFetch(res@resultSet, n, ...)
   columns <- convertFields(res@dbms, columns)
   columns <- dbFetchIntegerToNumeric(columns)
   colnames(columns) <- tolower(colnames(columns))

diff --git a/tests/testthat/test-fetchResults.R b/tests/testthat/test-fetchResults.R
@@ -39,6 +39,15 @@ for (testServer in testServers) {
     )
     expect_gt(dplyr::collect(andromeda$test2)$rowCount[1], 1)
     Andromeda::close(andromeda)
+
+    # dbFetch only fetches n rows
+    sql <- "SELECT * FROM @cdm_database_schema.vocabulary;"
+    sql <- SqlRender::render(sql,
+                             cdm_database_schema = cdmDatabaseSchema)
+    resultSet <- dbSendQuery(connection, sql)
+    data <- dbFetch(resultSet, n = 1)
+    dbClearResult(resultSet)
+    expect_equal(nrow(data), 1)
   })
 }