"ContentProvider Series 5" Review use ContentProvider additions and deletions to change contact data

Added: The data table is the general operation.

Find: A query that is generally related to multiple tables.

Modify: Also the data in the database table to be modified.

Delete: Queries involving multiple tables, and finally the data in the deleted tables.

In summary, all the actual data is stored in the database table. The Raw_contacts table and the data table are one-to-many relationships, and the Contacts table row is a synthesis of multi-line row_contacts tables because multiple accounts may be designed. See below for details:

"ContentProvider Series 5" Review use ContentProvider additions and deletions to change contact data