mybatis之多對一+多對多+一對多（部分）
阿新 • • 發佈：2018-12-19
1.com.dao(customerMapper+shopMapper)
public interface CustomerMapper { List<Customer> many2many(); } —————————————————————————————————————— <mapper namespace="com.dao.CustomerMapper"> <resultMap type="customer" id="mm"> <result property="customerName" column="customername"/> <collection property="olist" ofType="Orders"> <id property="ordersId" column="ordersid"/> <result property="ordersDate" column="ordersdate"/> <collection property="odlist" ofType="OrdersDetail"> <result property="quantity" column="quantity"/> <association property="product" javaType="product"> <result property="title" column="title"/> <result property="currentPrice" column="currentprice"/> </association> </collection> </collection> </resultMap> <select id="many2many" resultMap="mm"> select customername,o.ordersid,to_char(ordersdate,'yyyy-mm-dd') ordersdate, quantity,title,to_char(currentprice,'fm999990.0099') currentprice from customer c inner join orders o on c.customerid=o.customerid inner join ordersdetail od on o.ordersid=od.ordersid inner join product p on od.productid=p.productid </select> </mapper> —————————————————————————————————————— public interface ShopMapper { List<Product> many2one(); List<Shop> one2many(); } —————————————————————————————————————— <mapper namespace="com.dao.ShopMapper"> <resultMap type="com.pojo.Product" id="aaa"> <id property="productId" column="productId"/> <result property="title" column="title"/> <!-- association:用於對映一方實體 --> <association property="shop" javaType="com.pojo.Shop"> <result property="shopName" column="shopname"/> <result property="shopAddress" column="shopaddress"/> </association> </resultMap> <resultMap type="shop" id="bbb"> <id property="shopId" column="shopid"/> <result property="shopName" column="shopname"/> <result property="shopAddress" column="shopaddress"/> <!-- collection:用於對映多方實體 --> <collection property="plist" ofType="product"> <result property="title" column="title"/> </collection> </resultMap> <select id="many2one" resultMap="aaa"> select productid,title,shopname,shopaddress from product p inner join shop s on p.shopid=s.shopid order by productid </select> <select id="one2many" resultMap="bbb"> select s.shopid,shopname,shopaddress,title from shop s inner join product p on s.shopid=p.shopid </select> </mapper>
2.com.pojo(customer+orders+ordersDetail+product+shop)
public class Customer { private String customerId;
private String login; private String pwd; private String customerName; private String tel; private String address; private String gender; private String birthday; private List<Orders> olist;
} —————————————————————————— public class Orders { private String ordersId;
private String customerId;
private String ordersDate;
private String deliveryDate;
private String amount;
private List<OrdersDetail> odlist;
}
—————————————————————————— public class OrdersDetail {
private String ordersId; private String productId; private String quantity; private Orders orders; private Product product;
} —————————————————————————— public class Product {
private String productId;
private String areaId;
private String categoryId;
private String shopId;
private String title;
private String productDesc;
private String originalPrice;
private String currentPrice;
private String picture;
private String isCommend;
private String salesCount;
// product到shop表之間的關係為多對一
private Shop shop;
} —————————————————————————— public class Shop {
private String shopId;
private String shopName;
private String shopAddress;
private String contact;
// 對映多方實體(通過集合)
private List<Product> plist;
3.com.service(CustomerService+ShopService)
public class CustomerService {
public List<Customer> many2many() {
SqlSession session = null;
try {
session = MyBatisUtil.getSqlSession();
CustomerMapper mapper = session.getMapper(CustomerMapper.class);
return mapper.many2many();
} finally {
MyBatisUtil.close(session);
}
}
}
public class ShopService {
public List<Product> many2one() {
SqlSession session = null;
try {
session = MyBatisUtil.getSqlSession();
ShopMapper mapper = session.getMapper(ShopMapper.class);
return mapper.many2one();
} finally {
MyBatisUtil.close(session);
}
}
4.com.test(TestMyBatis)
public class TestMyBatis {
private ShopService service = new ShopService();
private CustomerService cs = new CustomerService();
@Test
public void testMany2one() {
List<Product> list = service.many2one();
for(Product p : list) {
String productId = p.getProductId();
String title = p.getTitle();
Shop shop = p.getShop();
String shopName = shop.getShopName();
String shopAddress = shop.getShopAddress();
System.out.println(productId + " " + title + " " + shopName + " " + shopAddress);
}
}
@Test
public void testOne2many() {
List<Shop> list = service.one2many();
for(Shop shop : list) {
String shopId = shop.getShopId();
String shopName = shop.getShopName();
String shopAddress = shop.getShopAddress();
System.out.println(shopId + " " + shopName + " " + shopAddress);
List<Product> plist = shop.getPlist();
for(Product p : plist) {
String title = p.getTitle();
System.out.println("\t\t" + title);
}
}
}
@Test
public void testMany2Many() {
List<Customer> list = cs.many2many();
System.out.println(list.size());
}
}
5.com.util(MyBatisUtil)
public final class MyBatisUtil {
private static SqlSessionFactory factory = buildSqlSessionFactory();
private MyBatisUtil() {}
private static final SqlSessionFactory buildSqlSessionFactory() {
String resource = "resources/mybatis-config.xml";
try {
InputStream inputStream = Resources.getResourceAsStream(resource);
return new SqlSessionFactoryBuilder().build(inputStream);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static final SqlSession getSqlSession() {
return factory.openSession();
}
public static final void close(SqlSession sqlSession) {
if(sqlSession != null) {
sqlSession.close();
}
}
}
6.resources(db.properties+mybatis-config.xml)
jdbc.driver=oracle.jdbc.OracleDriver
jdbc.url=jdbc:oracle:thin:@localhost:1521:orcl
jdbc.username=meitao
jdbc.password=123
___________________________________________
<configuration>
<!-- 外部屬性檔案 -->
<properties resource="resources/db.properties"/>
<settings>
<!-- 控制檯顯示sql語句(開發使用) -->
<setting name="logImpl" value="STDOUT_LOGGING"/>
</settings>
<typeAliases>
<package name="com.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!-- <mapper resource="resources/ShopMapper.xml"/> -->
<!-- 註冊指定包中的所有對映器介面(推薦) -->
<package name="com.dao"/>
</mappers>
</configuration>