CIS 515 Discussion post responses.

Respond to the colleagues posts regarding:

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A relational Database Model allows database users to analyze data thoroughly. To accomplish this, advanced commands such as UNION and INTERSECT may be used. Describe a business scenario where a UNION relational set operator may be used to merge two similar data sets. Within the context of your business scenario, analyze the analysis and data consistency advantages of using a UNION operator rather than simply merging two data sets into one result table.

VH’s post states the following:

A relational Database Model allows database users to analyze data thoroughly. To accomplish this, advanced commands such as UNION and INTERSECT may be used. Describe a business scenario where a UNION relational set operator may be used to merge two similar data sets. Within the context of your business scenario, analyze the analysis and data consistency advantages of using a UNION operator rather than simply merging two data sets into one result table.

Union command in the SQL combines with the results of two or more SELECT statements. In order for them to work each statement have to produce the same number of column. Data types have to be the same and the columns should be in the same order. For example, subset of employee information have to be selected from multiple tables within the database. Regardless of the department where the data is coming from hence employees for work.

SQL statement looks like this:

SELECT FName, LName, EEID, Position, Salary; FROM Finance; WHERE Salary>= 2500 UNION.

In a relational database model, the data can be analyzed by using the advance commands like UNION and INTERSECT. In a UNION relational set operator are used to with the combination of consumers’ data or data across database or across servers. UNION command have the ability to multiple tables with datasets that have the similar structures or vital information about the consumers or employees into one combined datasets.

Suppose you are tasked with finding common data elements amongst various data sets. Specify how an INTERSECT operator may assist you in accomplishing this task. Construct a query that can perform the same function as the INTERSECT operator without using the “INTERSECT” syntax within the query.

INTERSECT operator is almost the same as UNION command but the difference is the two SQL statements. UNION can act like an OR operator as well while INTERSECT command can act by an AND operator. See below how UNION query can function the same performance with the INTERSECT operator without “INTERSECT” syntax being used in the query.

SELECT EMPLOYEE. FIRSTNAME

EMPLOYEE. LASTNAME

EMPLOYEE.ADDRESS

EMPLOYEE.STATE

FROM EMPLOYEE D

INNER JION CUSTOMER J

ON M. FIRSTNAME=CUSTOMER. FIRSTNAME

AND EMPLOYEE.LASTNAME=CUSTOMER.LASTNAME

AND EMPLOYEE.ADRESSLINE1=CUSTOMER.ADDRESSLINE1

AND EMPLOYEE.CITYSTATE=J.CITY

GROUP BY EMPLOYEE.FIRSTNAME, EMPLOYEE.LASTNAME, EMPLOYEE.ADDRESSLINE1, EMPLOYEE.CITYSTATEZIPCODE

References:

Israel, M. & Jones, J.S. (2006). MCSE: SQL Server TM 2000 Design Study Guide.

Hoboken, John Wiley & Son.

Thakur, D. (2016). Relational Model. EComputer Notes. http://ecomputernotes.com/fundamental/what-is-a-database/relational-model