You need to fetch current currency rates for EUR to USD and EUR to CHF from the currencylayer API and store them into a MySQL database table.
https://currencylayer.com (you'll have to sign up for a free account)
- Define the table structure
- Provide a CLI PHP script which when executed fetches the data and stores it into the table
- Use the oceanapplications/currencylayer-php-client SDK
- You can use whatever frameworks & libraries you want (except the aforementioned API SDK which you are required to use)
- You can use any PHP7.1 features you want
- You can use any MySQL 5.7 features you want
| Task Component | Possible Questions |
|---|---|
| Add currencylayer API SDK via composer | What is semver? |
| Should composer.lock be committed or not? | |
| Use the SDK to fetch current currency rates for EUR → USD and EUR → CHF | |
| Define a MySQL table to store the rates | How do you set the PK and why? |
| Currencies as string, Enum or create an String → Id mapping? | |
| When using Enum, what are the advantages and disadvantages of each type? | |
| What MySQL data type do you use for money? Float or Decimal? Why? | |
| Store rates into this table | mysqli or PDO |
| What are the advantages of prepared statements? | |
| SQL injection: What is the conceptual difference between using prepared statements and escaping the data using the quote/escape function | |
| Bonus: Add a simple unit test | If not already happened: What would you abstract to make your code unit testable (dependency injection) and how would you do it? |