ogr_sql_sqlite_dialect.rst: improve phrasing

doc/source/user/ogr_sql_sqlite_dialect.rst

@@ -20,7 +20,7 @@ is dependent on the datasets.
   and, by default, pass the SQL statements directly to the underlying RDBMS.
   In these cases the SQL syntax varies in some particulars from OGR SQL.
   Also, anything possible in SQL can then be accomplished for these particular
-  databases. Only the result of SQL WHERE statements will be returned as
+  databases. Generally, only the result of SELECT statements will be returned as
   layers. For those drivers, it is also possible to explicitly request the
   ``OGRSQL`` and ``SQLITE`` dialects, although performance will generally be
   much less as the native SQL engine of those database systems.