One-to-one and one-to-one implementations in ibatis3

1. One-to-many



1. DB


Character Table t_user
Id bigint
Name varchar (20)
Age int

Item table t_user_goods
Id bigint
Goods_name varchar (20)
Uid bigint

2. sqlmap-config.xml


<? Xml version = "1.0" encoding = "UTF-8"?>
<! DOCTYPE configuration PUBLIC "-// ibatis.apache.org//DTD Config 3.0 //" http://ibatis.apache.org/dtd/ibatis-3-config.dtd ">
<Configuration>
<TypeAliases>
<TypeAlias type = "com. test. model. User" alias = "user"/>
<TypeAlias type = "com. test. model. UserGoods" alias = "userGoods"/>
</TypeAliases>
<Environments default = "development">
<Environment id = "development">
<TransactionManager type = "JDBC"/>
<DataSource type = "UNPOOLED">
<Property name = "driver"
Value = "net. sourceforge. jtds. jdbc. Driver"/>
<Property name = "url"
Value = "jdbc: jtds: sqlserver: // 192.168.0.101: 1433/guagua_vas_stock"/>
<Property name = "username" value = "guagua_web"/>
<Property name = "password" value = "123456"/>
</DataSource>
</Environment>
</Environments>
<Mappers>
<Mapper resource = "com/test/model/User. xml"/>
</Mappers>
</Configuration>

 3. User. java


Package com. test. model;

Import java. io. Serializable;
Import java. util. List;

Public class User implements Serializable {
Private static final long serialVersionUID = 8681358563101101660L;

Private long id;
Private String name;
Private int age;
Private List <UserGoods> goods;

--- Getter setter saving
}

4. UserGoods. java


Package com. test. model;

Import java. io. Serializable;

Public class UserGoods implements Serializable {

Private static final long serialVersionUID =-20173573481231610000l;
Private long id;
Private String name;
Private long uid;

-- Getter setter saving
}

 5. User. xml


<? Xml version = "1.0" encoding = "UTF-8"?>
<! DOCTYPE mapper PUBLIC "-// ibatis.apache.org//DTD Mapper 3.0 // EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<Mapper namespace = "user">
<ResultMap type = "user" id = "userMapper">
<Result property = "id" column = "id" jdbcType = "BIGINT"/>
<Result property = "name" column = "name" jdbcType = "VARCHAR"/>
<Result property = "age" column = "age" jdbcType = "INTEGER"/>
<Collection property = "goods" ofType = "java. util. List" select = "getGoodsById" column = "id"/>



</ResultMap>

<ResultMap type = "userGoods" id = "userGoodsMapper">
<Result property = "id" column = "id" jdbcType = "BIGINT"/>
<Result property = "name" column = "goods_name" jdbcType = "VARCHAR"/>
<Result property = "uid" column = "uid" jdbcType = "BIGINT"/>
</ResultMap>

<! -- Get the UserGoods object -->
<Select id = "getGoodsById" parameterType = "Integer" resultMap = "userGoodsMapper">
Select * from t_user_goods where uid =#{ id}
</Select>

<Select id = "getUserList" resultMap = "userMapper">
Select * from t_user
</Select>
</Mapper>

Note: resultMap does not seem to support cross-file use.

6. UserDao. java


Package com. test. dao;

Import java. util. List;
Import org. apache. ibatis. session. SqlSession;
Import com. bd. dao. IbatisSessionFactory;
Import com. test. model. User;

Public class UserDao {

Public List <User> getUserList (){
SqlSession session = IbatisSessionFactory. getSqlSession ();
List <User> list = (List) session. selectList ("getUserList ");
Session. commit ();
Session. close ();
Return list;
}

}

2. One-to-one


Assume that t_user and t_user_goods are in a one-to-one relationship.
 1. User. java


Package com. test. model;

Import java. io. Serializable;

Public class User implements Serializable {
Private static final long serialVersionUID = 8681358563101101660L;

Private long id;
Private String name;
Private int age;
Private UserGoods goods; // changed from List to UserGoods

-- Getter setter
}

2. User. xml


<? Xml version = "1.0" encoding = "UTF-8"?>
<! DOCTYPE mapper PUBLIC "-// ibatis.apache.org//DTD Mapper 3.0 // EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<Mapper namespace = "user">
<ResultMap type = "user" id = "userMapper">
<Result property = "id" column = "id" jdbcType = "BIGINT"/>
<Result property = "name" column = "name" jdbctype = "varchar"/>
<Result property = "Age" column = "Age" jdbctype = "integer"/>
<! -- Collection property = "goods" oftype = "Java. util. List" select = "getgoodsbyid" column = "ID"/-->
<Association property = "goods" column = "id" select = "getGoodsById"/>


</Resultmap>

<Resultmap type = "usergoods" id = "usergoodsmapper">
<Result property = "ID" column = "ID" jdbctype = "bigint"/>
<Result property = "name" column = "goods_name" jdbctype = "varchar"/>
<Result property = "uid" column = "uid" jdbctype = "bigint"/>
</Resultmap>

<! -- Get the usergoods object -->
<Select id = "getgoodsbyid" parametertype = "integer" resultmap = "usergoodsmapper">
Select * From t_user_goods where uid =#{ ID}
</SELECT>

<Select id = "getUserById" parameterType = "int" resultMap = "userMapper">
Select * from t_user where id =#{ id}
</Select>
</Mapper>

3. UserDao. java


Package com. test. dao;

Import java. util. List;
Import org. apache. ibatis. session. SqlSession;
Import com. bd. dao. IbatisSessionFactory;
Import com. test. model. User;

Public class UserDao implements UserDaoInte {
Public User getUserById (Long id ){
SqlSession session = IbatisSessionFactory. getSqlSession ();
User user = (User) session. selectOne ("getUserById", id );
Session. commit ();
Session. close ();

Return user;
}
}

4. Test code


Public static void main (String [] args ){
UserDao dao = new UserDao ();

User u = dao. getUserById (2L );
System. out. println ("name:" + u. getName ());
System. out. println ("goods:" + u. getGoods (). getName ());
}