[IBATIS-789] a new @ResultMap annotation to allow for @Select annotations on methods in mapper interfaces to use ResultMaps declared in XML files.

• Type: New Feature
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.0 GA Candidate
• Component/s: Core
• Labels: ResultMap annotation_processor
• Assignee: Unassigned
• Reporter: Travis Hein
• Created: 14/May/10 01:50
• Updated: 14/May/10 01:50

Description

Would it be possible to create a new annotation (or does one exist already and I just have not found it yet), where I can specify that @Select results should be a <resultMap> that exists in the mapper XML file ?

For example,

Consider a "country" table,

[code]
CREATE TABLE COUNTRY
(
ID bigint PRIMARY KEY NOT NULL,
CODE varchar(2) NOT NULL,
ISO_CODE varchar(3) NOT NULL,
NAME varchar(2147483647),
COUNTRY_CODE varchar(10),
ACTIVE boolean DEFAULT TRUE NOT NULL
);
[/code]

And the java Bean,

[code]
public class Country {
Long id;
String code; // 2 digit ISO country code
String isoCode; // 3 digit ISO country code
String name; // string name
String countryCode; // the telephone dialing prefix (e.g. +1)
boolean active = true;

// and all the get() set() methods for these bean properties
}
[/code]

And then the mapper interface,

[code]
public interface CountryDAO {

/**

• Selects all country entries.
• Though it appears when we use the annotations, we need to specify the results every time ?
  */
  @Select( value = { "select * from country where active = true" })
  @Results(value = { @Result(property="id"), @Result(property="code"), @Result(property="isoCode", column="iso_code"), @Result(property="name", column="name"), @Result(property="countryCode", column="country_code"), @Result(property="active", column="active") })
  List<Country> getAllActive();
  
  // TODO: all these methods would also be select queries, where I would want the same results map as above
  Country getById(Long id);
  Country getByCode(String code);
  Country getByIsoCode(String isoCode);
  }
  [/code]
  
  
  Where, instead of the @Results annotation, which would need to be duplicated with its nested @Result annotations on every select method that I want to return the same mapping, what I would wish to have would be something like a
  
  @ResultMap(value="myMapperID")
  
  annotation, where the myMapperID would be the ID of a <resultMap> I have declared in the mapper's xml file that will be included by the SqlMapConfig.xml (which I have anyway to bind to this mapper interface, and also because I have some more complex queries declared in the xml mapper file too).
  
  Where in this example, I already have a
  
  [code]
  <mapper namespace="CountryDAO">
  
  <resultMap type="Country" id="countryResult">
  <result property="id" column="id"/>
  <result property="code" column="code"/>
  <result property="isoCode" column="iso_code"/>
  <result property="name" column="name"/>
  <result property="countryCode" column="country_code"/>
  <result property="active" column="active"/>
  </resultMap>
  [/code]
  
  
  So this wishful @ResultMap annotation would then make the mapper interface look like:
  
  [code]
  public interface CountryDAO {
  
  @Select( value = { "select * from country where active = true" }

  )
  @ResultMap(value = "countryResult")
  List<Country> getAllActive();

// and now other things that want to select into this map can do so, re-using the single map declaration
// that is referenced in the xml.

@Select( value = { "select * from country where id = #

{id}

})
@ResultMap(value = "countryResult")
Country getById(Long id);

@Select( value = { "select * from country where code = #

})
@ResultMap(value = "countryResult")
Country getByCode(String code);

@Select( value = { "select * from country where isoCode = #

{isoCode}

})
@ResultMap(value = "countryResult")
Country getByIsoCode(String isoCode);
}
[/code]

I think having something like this @ResultMap annotation would be a good thing to have, what do you think?