How can I delete an element from the [Connected to] detail?

Question

I need to delete the connection to Documents and Leads in the [Connected to] detail of the [Activities] section.

Answer

For deleting the needed columns from the [Connected to] detail of the activities, execute the following request to the database:

DELETE FROM EntityConnection WHERE SysEntitySchemaUId = 'c449d832-a4cc-4b01-b9d5-8a12c42a9f89'
AND (ColumnUId = 'd6e94162-4354-413a-bc84-e118df5e852e'
OR ColumnUId = 'f6137557-741e-42f8-8bf6-69b2524a83f7')