For the view of Exercise 4.18, explain why the database system would not allow a tuple to be inserted into the database through this view.
For reference
For the database of Figure 4.12, write a query to find the ID of each employee with no manager. Note that an employee may simply have no manager listed or may have a null manager. Write your query using an outer join and then write it again using no outer join at all.
OUTER JOIN
select e.ID from employee e left outer join manages m on e.ID = m.ID
where m.manager_id is null;
NO OUTER
select e.ID from employee e where e.ID not in (select m.ID from manages m) or e.ID in (select m.ID from manages m where m.manager_id is null);
<h2>The Examples Of Users:</h2>
<h2>
The Answers Are:</h2>
- Formatted summary of information from a database
- User-friendly interface for adding to or retrieving information from a database
- Stores raw data in a relational database
- Retrieves specific information from a database. Can also be used to update, edit, and remove data
<h2>
Hope it helps*^-^*All Correct!?</h2>
5 I don’t think it’s good. I thought it was boring.
Answer:
I use Google cloud free tier for my Minecraft server
