Question

(TCO 7) Write a JOIN to display the instructor first and last names and the course description for the course the instructor is teaching Student Instructor Zipcode PK Student ID PK Instructor ID PK Zip Salutation First Name Last Name Street Address Phone Employer Registration Date Salutation First_Name Last_Name Street Address City State FK1 Zip FK1 Zip Section PK Section ID Course Course Section_Num Enrollment Start Date_Time Location PK Course ID PK,FK1 Section ID PK,FK2 Student ID Capacity FKI | Instructor-ID FK2 Course ID Description Cost Enroll_Date Final Grade FK1 Prerequisite 1. In your own words, what does it mean that the SQL Language is Non-Procedural? Have your answer focus on using Select statements 2. Here is an example SQL statement that uses the Select, From, Where, Group by and Having Clauses Select custD, count(Orders) from Orders where Ord Date> "2017-02-17 group by custD having count(orders)>5, Using the above SQL example, explain in your own words, the INTERNAL order of execution of each clause, clause by clause. In other words, explain which clause executes first and why it MUST execute first. Then explain which clause executes second and why that clause MUST execute second and so on. Use the above Select statement application to SUPPORT your understanding of the order of execution of each clause

Answer 1

JOIN QUERY:

SELECT Instructor.First_Name, Instructor.Last_Name, Course.Description FROM Instructor, Section, Course WHERE Instructor.Instructor_ID = Section.Instructor_ID AND Section.Course_ID = Course.Course_ID;

1. SQL - Non Procedural Language:
SQL - Structured Query Language is known as Non Procedural Language because whatever the data we need, we write them in sql in general terms. There are no specific rules to follow. Just writing in simple terms is enough. Also, no need of many operations like opening database and closing database and also for tables in sql. So, thats why it is considered to be as non-procedural language.

2. Select custID, count(Orders) from orders where OrdDate > '2017-02-17' group by custID having count(orders) > 5

solution:

First it selects all the different custID from Orders tables who ordered after the date '2017-02-17' and again it filters them so that their orders count should be greater than 5. This is because group by and having statement.