Hello,
In order to remove items from your database collection using code please refer to the links below:
https://www.wix.com/corvid/reference/wix-data.html#remove
https://www.wix.com/corvid/reference/wix-dataset.Dataset.html#remove
https://www.wix.com/corvid/forum/community-discussion/delete-all-database-values
https://www.wix.com/corvid/forum/community-discussion/delete-database-items-automatically-after-certain-time
Note that you can delete a collection from your database by following the instructions in the article below:
Removing a Collection from Your Database
In order to import data to your database collection, refer to the articles below:
Corvid Tutorial: Importing and Exporting Collection Data with Code
Importing Data to a Database Collection