hops-db

A very thin db layer on top of jdbc.

Uses the same structure like jdbc and adds functions to reduce boilerplate code.

Why?

Many Object relational mapping/JPA implementations are very powerful and complex and in some cases tricky. They have come a long way in the last 10 years but sometimes I still like to have a simple and thin layer on top of JDBC to make live a bit easier.

Basic examples

This is an annotation based sample that uses a single bean.

@Table
public class Simple {
  @Column(key = true)
  private int id = -1;
  
  @Column
  private String value;
  
  // getters and setters and constructors
}

Creating a Db object which provides functions, similar to a jdbc connection. AnnotationModelProvider reads annotations from the beans and provides those infomations to the Db instance.

AnnotationModelProvider models = new AnnotationModelProvider();
Db db = new Db("jdbc:h2:mem:name;USER=test;PASSWORD=test", models);

Create and save instance:

Simple simple = new Simple();
simple.setValue("foooo");
db.create(simple);

Find instance with id 1:

Simple simple = db.select(Simple.class).byPk(1).first();

Find all instances

List<Simple> simples = db.select(Simple.class).listAll();

Find some by where

List<Simple> simples = db.select(Simple.class).where("value like ? or value = ?", "bar%", "foo").listAll();

Count...

int howMany = db.select(Simple.class).where("value like ? or value = ?", "bar%", "foo").count();

Update instance:

Simple simple = db.select(Simple.class).byPk(1).first();
simple.setValue("bar");
db.update(bar);

Delete instance:

Simple simple = db.select(Simple.class).byPk(1).first();
db.delete(simple);