Warn on rows call in sqlite

Track situations where the value returned may be inaccurate and warn on those usages.

lib/DBDish/SQLite/StatementHandle.pm6

@@ -12,6 +12,8 @@ has $!statement_handle;
 has $!param-count;
 has Int $!row_status;
 has $!field_count;
+has Bool $!warn-on-inaccurate-rows = True;
+has Bool $!rows-is-accurate = False;
 
 method !handle-error(Int $status) {
     unless $status == SQLITE_OK {
@@ -46,6 +48,16 @@ method execute(*@params is raw --> DBDish::StatementHandle) {
         self!set-err($!row_status, sqlite3_errmsg($!conn));
     }
 }
+my role IntTrue { method Bool { self.defined } };
+
+# Override DBDish::StatementHandle to throw this error
+method rows() {
+    if (not $!rows-is-accurate and $!warn-on-inaccurate-rows) {
+        warn "SQLite rows result may not be accurate. "
+    }
+
+    self._rows();
+}
 
 method _row() {
     my $list = ();
@@ -71,6 +83,8 @@ method _row() {
         $!affected_rows++;
         self.reset-err;
         if ($!row_status = sqlite3_step($!statement_handle)) == SQLITE_DONE {
+            # Only after retrieving the final record is the rows value considered accurate.
+            $!rows-is-accurate = True;
             self.finish;
         }
     }

lib/DBDish/StatementHandle.pm6

@@ -71,7 +71,9 @@ submethod DESTROY() {
     self.dispose;
 }
 
-method rows {
+method rows() {self._rows}
+
+method _rows {
     my constant TRUE_ZERO = 0 but IntTrue;
     $!affected_rows.defined
             ?? $!affected_rows || TRUE_ZERO