Bus Commercial Management Tool(s)

# Bus Commercial Management Tool(s)
### Eric Stemmler
### 15. November 2021

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# Spreadsheets

- "What you see is what you get"

- graphical user interface
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.pull-right[
  ## Cons
  - keeping track of changes (!)

- data limits (e.g. 1,048,576 rows)

- translation issues
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.footnote[https://www.microsoft.com/en-us/microsoft-365/p/excel/cfq7ttc0k7dx/?activetab=pivot:regionofsystemrequirementstab
https://support.microsoft.com/en-us/office/excel-specifications-and-limits-1672b34d-7043-467e-8e27-269d656771c3]

???

- when several people work with the same Excel file and new data comes in, everyone needs to update the same file
- there is a small about of license costs for excel, however there are free alternatives such as libre office
- keeping track of local files is tedious: how do you make sure that everyone uses the same version and the same data?
- you could use version-control software for this
- the more complex functions in Excel are usually written in Visual Basic (VBA)
- Excel files independently from the computer's capacity that opens it have a fixed limit for the data it can hold

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# From Excel to Databases

- separat visual representation

- guarantees
  - atomicity
  - **consistency**
  - isolation
  - **durability**
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???

- databases are the de-facto standard how large company store structured data
- databases provide the means to store any data, even things like video data can be stored in databases.
- the only case where traditional databases cannot be used efficiently is when there is unstructured data- structured data is data that always comes in a known format, and that format does not change over time.
- independt from the database one can create or buy a user interface that provides an easier to use interface to interact with the database, e.g. generate a report, enter data, etc. (e.g. NaviCat for PostgreSQL)

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# Databases - everything in *one* file

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```sql
SELECT en.line_id, SUM(value)
FROM evidenca_numeric AS en
INNER JOIN evidenca_items AS ei ON ei.item_id = en.item_id 
WHERE en.year = '2019' 
AND ei.designation = 'Monthly Tickets Income'
GROUP BY en.line_id
```

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<div id="htmlwidget-f96e31bc9a7e28f22af6" style="width:100%;height:auto;" class="datatables html-widget"></div>
<script type="application/json" data-for="htmlwidget-f96e31bc9a7e28f22af6">{"x":{"filter":"none","vertical":false,"data":[["1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16"],["1","10","11","12","13","14","15","2","3","4","5A","5B","6","7","8","9"],[50841000,34343300,54566000,29479000,816520000,84971000,119612000,32361000,53834000,36257000,39532000,36821000,15685000,24401000,58202000,36314000]],"container":"<table class=\"display\">\n  <thead>\n    <tr>\n      <th> <\/th>\n      <th>line_id<\/th>\n      <th>sum<\/th>\n    <\/tr>\n  <\/thead>\n<\/table>","options":{"columnDefs":[{"targets":2,"render":"function(data, type, row, meta) {\n    return type !== 'display' ? data : DTWidget.formatCurrency(data, \"ALL \", 2, 3, \",\", \".\", true);\n  }"},{"className":"dt-right","targets":2},{"orderable":false,"targets":0}],"order":[],"autoWidth":false,"orderClasses":false}},"evals":["options.columnDefs.0.render"],"jsHooks":[]}</script>

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# From Databases to Web-based

- user accounts

- easy to translate

- centralized: always up to date
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# Thank You