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 rankings (ranking_date VARCHAR, tours INTEGER)

### Question ###
Find the total number of tours for each ranking date.

### Accurate SQL ###

SELECT SUM(tours), ranking_date FROM rankings GROUP BY ranking_date