Will you consider taking the Dao/Model pattern of JDBI and SpringData?

[gencube]

Will you please also consider taking these code pattern from JDBI or SpringData?
http://jdbi.org/

public interface MyDAO
{
  @SqlUpdate("create table something (id int primary key, name varchar(100))")
  void createSomethingTable();

  @SqlUpdate("insert into something (id, name) values (:id, :name)")
  void insert(@Bind("id") int id, @Bind("name") String name);

  @SqlQuery("select name from something where id = :id")
  String findNameById(@Bind("id") int id);

  /**
   * close with no args is used to close the connection
   */
  void close();
}```

OR Model+Repository pattern from springdata:
https://github.com/spring-projects/spring-data-book/tree/master/mongodb

```java
package com.oreilly.springdata.mongodb.core;
import org.springframework.data.repository.Repository;

/**
 * Repository interface to access {@link Customer}s.
 * 
 * @author Oliver Gierke
 */
public interface CustomerRepository extends Repository<Customer, Long> {

    /**
     * Returns the customer with the given identifier.
     * 
     * @param id
     * @return
     */
    Customer findOne(Long id);

    /**
     * Saves the given {@link Customer}. #
     * 
     * @param customer
     * @return
     */
    Customer save(Customer customer);

    /**
     * Returns the {@link Customer} with the given {@link EmailAddress}.
     * 
     * @param string
     * @return
     */
    Customer findByEmailAddress(EmailAddress emailAddress);
}

However have OPTIONS to handle the commonly used pattern in Reactive or Sync model??

[gencube]

It would be a good pattern to reduce the LOC for myql coding and also implemented efficiently.

[davidmoten]

Yeah, I like the idea of the bind interface from jdbi. I'll have to ponder how it will fit in with the reactive model. Using dynamic proxies with an interface would be nicer than using the mapped class.

[gencube]

👯
Please do consider this mapper feature also:
http://jdbi.org/sql_object_api_queries/

public class SomethingMapper implements ResultSetMapper<Something>
{
  public Something map(int index, ResultSet r, StatementContext ctx) throws SQLException
  {
    return new Something(r.getInt("id"), r.getString("name"));
  }
}
...
 @SqlQuery("select id, name from something where id = :id")
  @Mapper(SomethingMapper.class)  // <<< Fast(better than Reflection) and ORM
  Something findById(@Bind("id") int id);

AND also

http://jdbi.org/sql_object_api_dml/

public static interface Update
{
...
 @SqlUpdate("update something set name = :name where id = :id")
  int update(@BindBean Something s);  // <<< @BindBean
}

[davidmoten]

Thank you very much for that stuff. I've made a minor start by improving autoMap so you can use an annotated interface. See here. I've just released it as 0.5.8.

I'll keep checking this stuff out and add things bit by bit.

[gencube]

Good work!! Even cleaner code. I too was considering AutoMap Example for the @Mapper(SomethingMapper.class) Suggestion. How would that also impact the update/insert example?

[davidmoten]

The mapper functionality to avoid reflection overhead already exists (though not with an annotation):

        String name = db()
                .select("select name from person order by name")
                .get(new Func1<ResultSet, String>() {
                    @Override
                    public String call(ResultSet rs) {
                        try {
                            return rs.getString(1);
                        } catch (SQLException e) {
                            throw new RuntimeException(e);
                        }
                    }
                }).first().toBlocking().single();
    }

Using java 8 and rxjava-extras Checked class:

        String name = db()
                 .select("select name from person order by name")
                .get(Checked.f1(rs -> rs.getString(1))
                .first().toBlocking().single();

[davidmoten]

Updated docs about custom mapping:
https://github.com/davidmoten/rxjava-jdbc/blob/master/README.md#custom-mapping

I would like to have get be called with say a CheckedFunc1 that can throws an Exception so we can get rid of the try catch.

[davidmoten]

rxjava-jdbc 0.5.9 will use a new ResultSetMapper<T> interface instead of a Func1<ResultSet,Boolean> as parameter to get.

This will enable usage like:

Observable<Person> persons = db()
                .select("select name, score from person order by name")
                .get(rs -> new Person(rs.getString(1), rs.getInt(2)));

[gencube]

The above progress looks good:

Actually, I am new to rxjava, and like to clarify with another feature, you recommended not to use
.toBlocking():

... 
Observable<Person> persons = db()
                .select("select name, score from person order by name")
                .get(rs -> new Person(rs.getString(1), rs.getInt(2)))
               .first().toBlocking().single();
// vs

// I knows this can be run async and automatically in multithread as you 
Observable<Person> persons = db()
                .select("select name, score from person order by name")
                .get(rs -> new Person(rs.getString(1), rs.getInt(2)));

IF I have JaxRS, because of existing code base on client side:

@Path("/persons")
public class PersonController {

[davidmoten]

toBlocking is ok, you just get more benefit from one flow as opposed to many discrete flows.

[gencube]

Accidentally, closed.
IF I have JaxRS, because of existing code base on client side:

@path("/persons")
public class PersonController {

@GET    
@Produces({"application/json", "application/xml"})
public List<Person> get() {
    List<Person> persons= ...
    // How do I use rxjava + jdbc ASYNC here???
   ...
    return persons.toArray();
}

}

[gencube]

try { return new Person(rs.get(1), rs.get(2));}
catch (SqlException e) { throw new RuntimeException(e);}} <<< Too noisy.

How to hide it with the this feature??
https://github.com/ReactiveX/RxJava/wiki/Error-Handling-Operators

[davidmoten]

toBlocking is ok for those application boundaries. If an error occurs it will rethrow it as a RuntimeException of some sort. There are other ways of doing things using a Subscriber which I can show you if you want.