- Data frames resulting from a query always have unique non-empty col…

…umn names (r-dbi/DBItest#137).

R/names.R

@@ -0,0 +1,32 @@
+set_tidy_names <- function(x) {
+  new_names <- tidy_names(names2(x))
+  names(x) <- new_names
+  x
+}
+
+names2 <- function(x) {
+  name <- names(x)
+  if (is.null(name)) {
+    name <- rep("", length(x))
+  }
+  name
+}
+
+tidy_names <- function(name) {
+  name[is.na(name)] <- ""
+  append_pos(name)
+}
+
+append_pos <- function(name) {
+  need_append_pos <- duplicated(name) | name == ""
+  if (any(need_append_pos)) {
+    rx <- "[.][.][1-9][0-9]*$"
+    has_suffix <- grepl(rx, name)
+    name[has_suffix] <- gsub(rx, "", name[has_suffix])
+    need_append_pos <- need_append_pos | has_suffix
+  }
+
+  append_pos <- which(need_append_pos)
+  name[append_pos] <- paste0(name[append_pos], "..", append_pos)
+  name
+}

R/query.R

@@ -49,7 +49,8 @@ setMethod("dbFetch", "MariaDBResult",
     if (trunc(n) != n) stopc("n must be a whole number")
     ret <- result_fetch(res@ptr, n = n)
     ret <- convert_bigint(ret, res@bigint)
-    sqlColumnToRownames(ret, row.names)
+    ret <- sqlColumnToRownames(ret, row.names)
+    set_tidy_names(ret)
   }
 )
 
@@ -164,7 +165,9 @@ NULL
 #' @export
 #' @rdname result-meta
 setMethod("dbColumnInfo", "MariaDBResult", function(res, ...) {
-  result_column_info(res@ptr)
+  df <- result_column_info(res@ptr)
+  df$name <- tidy_names(df$name)
+  df
 })
 
 #' @export