opentelemetry-instrumentation-sqlalchemy: Fix exception on empty query

Author: plentydone

instrumentation/opentelemetry-instrumentation-sqlalchemy/src/opentelemetry/instrumentation/sqlalchemy/engine.py

@@ -239,9 +239,9 @@ def _operation_name(self, db_name, statement):
             # For some very special cases it might not record the correct statement if the SQL
             # dialect is too weird but in any case it shouldn't break anything.
             # Strip leading comments so we get the operation name.
-            parts.append(
-                self._leading_comment_remover.sub("", statement).split()[0]
-            )
+            split_query = self._leading_comment_remover.sub("", statement).split()
+            if split_query:
+                parts.append(split_query[0])
         if db_name:
             parts.append(db_name)
         if not parts: