There are four types of operator in QBASIC. They are Arithmetic operators,relational operators,logical operators and sting operator .a. arithmetic operators. Arithmetic operators are used to preform mathematical calculations like addition, subtraction, division, multiplication and exponential
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);
Answer:
Please check the explanation.
Explanation:
The US education department mentioned that in 1900 there were only 10% of students enrolled in the schools, however by the end of 1992, the percentage increased by 85% and it became 95%. In 1930 1 million students were enrolled in university. And by 2012, it became 21.6 million. The teachers began to follow a new type of teaching, and the academics began to follow a special method for communique, education as well as for helping the students understand the concepts.
Though, after the 1980s the personal computer came into being in schools and colleges. Since then numerous versions of PC have originated in the marketplace as well as mobiles tracked by Smartphones, and now nearly 100% of people in the US have smartphones. Virtual reality, augmented reality, AI, Machine learning. etc. has cemented the way for the virtual classrooms. Also, each subject is now up with fruits and not just-food. The consequence is such a delightful setup of the Virtual schoolrooms in the entire US, and all over the ecosphere. The projectors, VR devices, AI applications for education, online classroom facility, Electronic version of chalkboards, and in fact everything is no sophisticated, and it is making not only teaching easy but learning as well. And the result is, students are ending up with better results, and teachers seem to be happier and more relaxed. And that is making school management satisfied as well.
Answer:
Check the explanation
Explanation:
A relation schema is the fundamental schema for a table. Which is In a relational kind of database (what individuals naturally refer to when they talk about database) each take can be referred to as a "relation" . therefore a relational schema is the design for the table.
kindly check the attached image below to see the step by step solution to the question.
Answer:
Namespaces ( B )
Explanation:
The codes in the C++ standard library are organized into folders Known as namespaces .
namespaces are general used to organize various codes into logical groups to avoid name collisions that may occur when there is the presence of multiple libraries in a code base.
