Fixed #29541 -- Fixed Cursor.execute() crash when setinputsizes() is called without arguments wit cx_Oracle 6.4.

django/db/backends/oracle/base.py

@@ -459,6 +459,7 @@ class FormatStylePlaceholderCursor:
                 for k, value in params.items():
                     if value.input_size:
                         sizes[k] = value.input_size
+            if sizes:
                 self.setinputsizes(**sizes)
         else:
             # It's not a list of dicts; it's a list of sequences
@@ -467,6 +468,7 @@ class FormatStylePlaceholderCursor:
                 for i, value in enumerate(params):
                     if value.input_size:
                         sizes[i] = value.input_size
+            if sizes:
                 self.setinputsizes(*sizes)
 
     def _param_generator(self, params):