BUG: allow sql using %% with postgres (pandas-dev#35484)

Author: machow

pandas/io/sql.py

@@ -1159,7 +1159,7 @@ def run_transaction(self):
 
     def execute(self, *args, **kwargs):
         """Simple passthrough to SQLAlchemy connectable"""
-        return self.connectable.execution_options(no_parameters=True).execute(
+        return self.connectable.execution_options().execute(
             *args, **kwargs
         )
 
@@ -1291,6 +1291,10 @@ def read_query(
         read_sql
 
         """
+        if isinstance(sql, str) and params is None:
+            from sqlalchemy.sql import text
+            sql = text(sql)
+
         args = _convert_params(sql, params)
 
         result = self.execute(*args)