Submit a document with your interpretation of the posted problem and address the
ID: 3847544 • Letter: S
Question
Submit a document with your interpretation of the posted problem and address the following:1/ in terms of the relations shown in the given database instructions, identify the appearance of the relation result after executing each of the instructions.
Second individual assignment [Individual Hand-In] Relations While there are many varieties of databases, the relational database model is the mode utilized in common systems such as oracle, MysQL. MS SQL Server and MS Access. As such, it is imperative to understand, recognize, and interpret relations within these databases. That said, consider the following relational database instructions Employees Email address tion john@abxz com 5 John John Mary smith@abxz.com 3 Philip hilipx@abxz.com 5 Department Manager Name Floor Karen avid a. RESULT PROJECT Location from Employees b. RESULT SELECT from Employees where Location 5 c. RESULT PROJECT Floor from Department d. RESULT JOIN Employees and Department where Employees. Location Department Floor In this Hand-In Assignment, you will decipher the presented database instructions, and determine relation RESULT. To prepare for this Assignment: Review your Weekly Learning Resources with a focus on relational databases. Analyse the given database instructions. Analyse each of the relations within the given database instructions. Reflect on the relation RESULT after executing all database instructions
Explanation / Answer
a) The command PROJECT is used to take out the the required columns from the relation ( table)
Here, The intruction means PROJECT Locatin from Employees. ie From the table Employees display the colum location. The output will be a table with 1 colum and 3 rows as follows
This displays the information about all the locations possibly the employees can have
b) SELECT command takes out the rows from a table which matches the condition given in the instruction. The condition comes after the ' where statement' . Here the condition is "Location = 5. " . This means the RESULT will have the rows in which the colum value corresponding to Location is 5. The table has 2 such rows
This shows the information of people at location 5
c)
The command PROJECT is used to take out the the required columns from the relation ( table)
Here, The intruction means PROJECT Floors from Department. ie From the table Department display the colum Floors. The output will be a table with 1 colum and 2 rows as follows
This displays the information about all the floors possibly the departments can have
d)
A JOIN clause is used to combine rows from two or more tables, based on a related column between them.When applying join on the condtion EmployeeLocation = floor#, the table will be joined such that to find the relation betwen the values in employee table and the department table. Here John and Phlip has their location at 5 . And there is an entry in department where the floor is 5 . So details of John and Philip will be represented in result where it is merged to David ( the output wont be displayed here since ther is not select command).
Location 5 3 5