Because my major is computer programming, database technology is
based requite. Databases technology very useful in the life and my career.
Modification problems: When making changes to the lists, let li
The formal name for a thing that is being tracked is entity, which is defined as something of
importance to the user that needs to be represented in the database.
Example: user, order, a relation
1. Deleted row:
too much data lost
2. Update row: inconsistent data
3. Inserted row: data missing