Headline

Sum up the salaries of all employees

Description

The salaries of a company's employees are to be summed up. Let's assume that the management of the company is interested in the salary total as a simple indicator for the amount of money paid to the employees, be it for a press release or otherwise. Clearly, any real company faces other expenses per employee, which are not totaled in this manner.

Motivation

The feature may be implemented as a query, potentially making use of a suitable query language. Conceptually, the feature corresponds to a relatively simple and regular kind of query, i.e., an iterator-based query, which iterates over a company' employees and aggregates the salaries of the individual employees along the way. It shall be interesting to see how different software languages, technologies, and implementations deal with the conceptual simplicity of the problem at hand.

Illustration

Totaling salaries in SQL

Consider the following Language:SQL query which can be applied to an instance of a straightforward relational schema for companies. We assume that all employees belong to a single company; The snippet originates from Contribution:mySqlMany.

SELECT SUM(salary) FROM employee;

Totaling salaries in Haskell

Consider the following Language:Haskell functions which are applied to a simple representation of companies.

-- Total all salaries in a company
total :: Company -> Float
total = sum . salaries

-- Extract all salaries in a company
salaries :: Company -> [Salary]
salaries (n, es) = salariesEs es

-- Extract all salaries of lists of employees
salariesEs :: [Employee] -> [Salary]
salariesEs [] = []
salariesEs (e:es) = getSalary e : salariesEs es

-- Extract the salary from an employee
getSalary :: Employee -> Salary
getSalary ( ,  , s) = s

Relationships

Guidelines

  • The name of an operation for summing up salaries thereof should involve the term "total". This guideline is met by the above illustration, if we assume that the shown SQL statement is stored in a SQL script with name "Total.sql". By contrast, if OO programming was used for implementation, then the names of the corresponding methods should involve the term "total".
  • A suitable demonstration of the feature's implementation should total the salaries of a sample company. This guideline is met by the above illustration, if we assume that the shown SQL statement is executed on a database which readily contains company data. All such database preparation and query execution should preferably be scripted. Likewise, if OO programming was used, then the demonstration could be delivered in the form of unit tests.

Metadata


Ralf Lämmel edited this article at Mon, 26 Jun 2017 20:20:06 +0200
Compare revisions Compare revisions

User contributions

    This user never has never made submissions.

    User edits

    Syntax for editing wiki

    For you are available next options:

    will make text bold.

    will make text italic.

    will make text underlined.

    will make text striked.

    will allow you to paste code headline into the page.

    will allow you to link into the page.

    will allow you to paste code with syntax highlight into the page. You will need to define used programming language.

    will allow you to paste image into the page.

    is list with bullets.

    is list with numbers.

    will allow your to insert slideshare presentation into the page. You need to copy link to presentation and insert it as parameter in this tag.

    will allow your to insert youtube video into the page. You need to copy link to youtube page with video and insert it as parameter in this tag.

    will allow your to insert code snippets from @worker.

    Syntax for editing wiki

    For you are available next options:

    will make text bold.

    will make text italic.

    will make text underlined.

    will make text striked.

    will allow you to paste code headline into the page.

    will allow you to link into the page.

    will allow you to paste code with syntax highlight into the page. You will need to define used programming language.

    will allow you to paste image into the page.

    is list with bullets.

    is list with numbers.

    will allow your to insert slideshare presentation into the page. You need to copy link to presentation and insert it as parameter in this tag.

    will allow your to insert youtube video into the page. You need to copy link to youtube page with video and insert it as parameter in this tag.

    will allow your to insert code snippets from @worker.