Altering a table to add a collection

Adding or changing collection columns to a table with the ALTER TABLE command.

The ALTER TABLE command can be used to add new collection columns to a table and to alter the column type of an existing column.

Procedure

Alter the table cycling.upcoming_calendar to add a collection map description that can store a description for each race listed.
```
cqlsh> ALTER TABLE cycling.upcoming_calendar ADD description map<text,text>;
```

After updating cycling.upcoming_calendar table to insert some data, description can be displayed.

cqlsh> UPDATE cycling.upcoming_calendar 
SET description = description + {'Criterium du Dauphine' : "Easy race', 'Tour du Suisse' : 'Hard uphill race'} WHERE year = 2015 AND month = 6;