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_64029 ( "Class to 1928" text, "Class from 1928" text, "Seats" text, "Quantity" real, "Year(s) of Manufacture" text, "Remarks" text )

### Question ###
Which class from 1928 had a class to 1928 of BDi-21?

### Accurate SQL ###

SELECT "Class from 1928" FROM table_64029 WHERE "Class to 1928" = 'bdi-21'