A Simple Query

Wouldn't it be nice if you could declare a method on an interface, annotate it with a SQL query, and there was a toolkit that would generate an implementation for you?

interface QuerySession extends Session {
    @Query("select ZIP from ADDRESSES where NAME=$1")
    String zipCode(String name);
}

public static void main(String[] args] {
    QuerySession session = Connecting.to("jdbc://my-database").open(QuerySession.class);
    System.out.println("Smith's zip code is: " + session.zipCode("Smith"));
    session.close();
}

A Less Simple Query

When we query a databse, we might want to get more than one record, or read multiple fields. Define an interface with accessors for the field values, and return it from the query method:

interface Addresses extends Results {
    String name();
    String street();
    String city();
    String state();
    String zip();
}

interface AddrSession extends Session {
    @Query("select * from ADDRESSES where NAME=$1")
    Addresses forName(String name);
}

public static void main(String[] args] {
    AddrSession session = Connecting.to("jdbc://my-database").open(AddrSession.class);
    Addresses addrs = session.forName("Jones");
    while (addrs.next()) {
        System.out.println(addrs.name() + " lives in city: " + addrs.city());
    }
    addrs.close();
    session.close();
}

Updates, Inserts

copalis.sql does those too. Check out out the samples.

Credits

copalis.sql was inspired by TMDBC, but departs from it in these respects:

• Uses standard JDBC and is not tied to Postgres
• Uses runtime dynamic proxies rather than compile-time code generation
• Data access interfaces are wrappers around ResultSet, not Java Beans