Putting it all together

You should now know enough to build an example that does what we described at the beginning of the chapter. We have learned the following:

• How to read a TOML file to parameterize the program
• How to load the data regarding products and sales into memory, specified in a JSON file and in an XML file
• How to store all of this data in three places: a SQLite DB file, a PostgreSQL database, and a Redis key-value store

The source code of the complete example is found in the transformer project. To run it, open its folder and type in cargo run ../data/config.toml. If everything is successful, it will recreate and populate the SQLite database contained in the data/sales.db file, the PostgreSQL database, which can be accessed from localhost on port 5432 and is named Rust2018, and the Redis store, which can be accessed from localhost. Then, it will query the SQLite and PostgreSQL databases for the number of rows in their tables, and it will print the following:

SQLite #Products=4. 
SQLite #Sales=5. 
PostgreSQL #Products=4. 
PostgreSQL #Sales=5. 

So, we have now seen a rather broad example of data manipulation.