for command queries, dbFetch() returns empty data frame

instead of raising an error

Author: Kirill Müller

R/result.R

@@ -16,6 +16,8 @@ setAs("MySQLResult", "MySQLConnection", function(from) {
 
 mysqlFetch <- function(res, n, ...) {
   rel <- .Call(RS_MySQL_fetch, res@Id, nrec = as.integer(n))
+  if (is.null(rel))
+    return(data.frame())
 
   if (length(rel) > 0) {
     n <- length(rel[[1]])

src/result.c

@@ -259,7 +259,7 @@ SEXP RS_MySQL_fetch(SEXP rsHandle, SEXP max_rec) {
   result = RS_DBI_getResultSet(rsHandle);
   flds = result->fields;
   if(!flds)
-    error("corrupt resultSet, missing fieldDescription");
+    return R_NilValue;
   num_rec = asInteger(max_rec);
   expand = (num_rec < 0);   // dyn expand output to accommodate all rows
   if(expand || num_rec == 0){