Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_64780 ( "Constituency number" text, "Name" text, "Reserved for ( SC / ST /None)" text, "District" text, "Number of electorates (2009)" real )

### Question ###
What's the constituency number of the Seoni district and has none reserved?

### Accurate SQL ###

SELECT "Constituency number" FROM table_64780 WHERE "Reserved for ( SC / ST /None)" = 'none' AND "District" = 'seoni'