# Data types & Scales

* Data represented in a computer
* Data types
* Data scales
* Meta data

**Preparation:**

Data Literacy Fundamentals, Ben Jones, Ch: 3,4

[SELECT](https://www.mysqltutorial.org/mysql-select-statement-query-data.aspx)

[WHERE](https://www.mysqltutorial.org/mysql-where/)

[AND](https://www.mysqltutorial.org/mysql-where/)

## Exercise 1 - Pairs

Find mindst 1 konkret eksempel, der kan repræsenteres på hver skala.

* Nominal
* Ordinal
* Interval
* Ratio
* Skriv en detaljeret forklaring på: Hvorfor/hvordan vi kan observere at eksemplet kan repræsenteres på en given skala.

Eksempel på hvordan man **ikke** skal gøre:

* Nominal skala: Farve
* Det siger sig selv, vi synes godt farver kan repræsenteres på en nominal skala

## Exercise 2 - Pairs

[Spotify-data](https://www.kaggle.com/datasets/paradisejoy/top-hits-spotify-from-20002019)

**Identificer:**

* Datatype for hver kolonne
* Skala for hver kolonne
* Begrund hvert valg

## Exercises 3 - Pairs

* Explain: What does the dataset contain?

Retrieve the following data by querying:

* All pokemon with all their columns
* Only the name of all pokemon
* All grass type pokemon
* All pokemon with a speed above 56
* All pokemon with a secondary type
* Is MySQL case sensitive? Explain with an example

## Exercises 4 - Pairs

Retrieve the following data by querying:

* The name of all pokemon with a special defence less than 56 and a special attack higher than 65
* All grass type pokemon starting with the letter 'B'
* All fire or ground pokemon with an attack higher than 50
* The first 10 pokemon by pokedex number ordered by their speed
  * <https://www.mysqltutorial.org/mysql-limit.aspx>
  * <https://www.mysqltutorial.org/mysql-order-by/>

**Advanced queries (Optional)**

* All pokemon without a secondary type, starting with 'P' with an attack or defence above 40
  * <https://www.mysqltutorial.org/mysql-like/>
* The 10 pokemon with the highest attack
* All pokemon that contains the latter 'C' in their name - ordered alphabetically
