Java Holiday Calendar 2016 (Day18): Easily Create Database Content

Today's tip is about creating database content. There are a number of ways to do this, ranging from writing our own entity beans combined with using JDBC directly to just fully automating the entire process.

Suppose we already have a database table like this:

mysql> explain country
+------------+-------------+------+-----+---------+----------------+
| Field      | Type        | Null | Key | Default | Extra          |
+------------+-------------+------+-----+---------+----------------+
| id         | int(11)     | NO   | PRI | NULL    | auto_increment |
| name       | varchar(45) | YES  | UNI | NULL    |                |
| local_name | varchar(45) | YES  |     | NULL    |                |
| code       | int(11)     | YES  |     | NULL    |                |
| domain     | varchar(10) | YES  |     | NULL    |                |
+------------+-------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)

Then we could add the Speedment plugin and dependency to our POM and launch the Speedment graphic tool, which will analyze the database and generate code automatically for us.

After generation, we can do this:

Initialization

final MyApplication app = new MyApplicationBuilder()
    .withPassword("myPwd729") // Replace with the real pwd
    .build();

final CountryManager countries = app.getOrThrow(CountryManager.class);

Insert DB Content

countries.persist(
    new CountryImpl()
        .setName("Sweden")
        .setLocalName("Sverige")
        .setCode(40)       // Intentionally wrong, should be 46!!
        .setDomain(".se")
);

Update DB Content

countries.stream()
    .filter(Country.NAME.equal("Sweden"))  // Filter out Sweden
    .map(c -> c.setCode(46))               // Update code to 46
    .forEach(countries.updater());         // Apply the database updater

Read more about Speedment on GitHub here.

Follow the Java Holiday Calendar 2016 with small tips and tricks all the way through the winter holiday season.