ibtais所谓的级联

iBATIS 2.0 requires JDK 1.4
ibatis是用xml描述来实现javabean与sql这间的对应也就是说半自动的ibatis一个map实现一条sql语句,所以个人认为ibatis没有真正配置上的级联操作,所谓的级联操作只是在service的方法中调用多个dao的事务处理。只有事务才能保多条sql语句的同时处理。

 

首先是ibatis的配置

<!--configLocation属性指定了ibatis的sqlmap-config.xml文件对应的路径--><!--dataSource配置省略--><bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean"> <property name="configLocation" value="classpath:sqlmap-config.xml"/> <property name="dataSource" ref="dataSource"/></bean>

 

以下是ibatis事务的配置

<!-- Transaction manager for a single JDBC DataSource--><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/></bean><!-- 定义事务代理基类,通过方法名前缀绑定事务,即以tran开头的方法才会执行事务处理 --><bean id="baseTransactionProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true"><property name="transactionManager" ref="transactionManager"/> <property name="transactionAttributes"> <props> <prop key="tran*">PROPAGATION_REQUIRED</prop> </props> </property></bean>

通过以上的配置基本上就可以使用service来调用事务了

<!-- (*)只有通过下面定义的beanID来取service时，才能享受声明式事务功能 --><bean id="employeeServiceProxy" parent="baseTransactionProxy"><property name="target"><ref local="employeeService" /></property></bean>

以上ibatis事务service完全配好，下面通过具体代码说明

Employee.xml(ibatis的sql-map文件)

 <?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd"><sqlMap namespace="Employee"><!--引进需要的java对象Employee,取别名employee--><typeAlias alias="employee"type="com.fanchina.nenkin.biz.bo.Employee" /><typeAlias alias="spouse" type="com.fanchina.nenkin.biz.bo.Spouse" /><typeAlias alias="child" type="com.fanchina.nenkin.biz.bo.Child" /><resultMap id="employee-baseinfo-map" class="employee"><result property="employeeId" column="employee_id" /><result property="employeeCode" column="employee_code" /><result property="firstName" column="first_name" /><result property="lastName" column="last_name" /><result property="sex" column="sex" /><result property="birthday" column="birthday" /><result property="status" column="status" /><result property="createDate" column="create_date" /><result property="createRealId" column="create_real_id" /><result property="updateDate" column="update_date" /><result property="updateRealId" column="update_real_id" /><result property="spouse" column="employee_id"select="Employee.getSpouseByEmployeeId" /><!--查询employee时同时查出spouse信息--><result property="childs" column="employee_id"select="Employee.getChildByEmployeeId" /><!--查询employee时同时查出child信息--></resultMap><insert id="insertEmployee" parameterMap="emp-param-map">insert into employee(employee_id,employee_code,first_name,last_name,sex,birthday,status,create_date,create_real_id,update_date,update_real_id)values(?,?,?,?,?,?,?,?,?,?,?)</insert><select id="getSpouseByEmployeeId" parameterClass="java.lang.String"resultMap="spouse-map">SELECT * FROM spouse WHERE employee_id = #employeeId# andspouse.`status`= 1</select><select id="getChildByEmployeeId" parameterClass="java.lang.String"resultMap="child-map">SELECT * FROM child WHERE employee_id = #employeeId# andchild.`status` = 1</select></sqlMap>

(spouse-map和child-map未配置)

从以上代码中可以看出employee除了自己基本属性外还有spouse和child属性，也就是说涉及到employee的操作都有可能要更新spouse和child,就是级联操作。

 

第一步：DAO调用sql处理

EmployeeDAOImpl.java(dao文件)
public class EmployeeDAOImpl extends SqlMapClientDaoSupport implements EmployeeDAO {
     public void insert(Employee bo) {
           getSqlMapClientTemplate().insert("Employee.insertEmployee",bo);
     }
}
spouseDAO,childDAO省略

 

第二步：Service调用DAO间接调用sql处理

public class EmployeeServiceImpl implements EmployeeService {private EmployeeDAO employeeDAO;private SpouseDAO spouseDAO;private ChildDAO childDAO;public EmployeeDAO getEmployeeDAO() {return employeeDAO;}public void setEmployeeDAO(EmployeeDAO employeeDAO) {this.employeeDAO = employeeDAO;}public ChildDAO getChildDAO() {return childDAO;}public void setChildDAO(ChildDAO childDAO) {this.childDAO = childDAO;}public SpouseDAO getSpouseDAO() {return spouseDAO;}public void setSpouseDAO(SpouseDAO spouseDAO) {this.spouseDAO = spouseDAO;}//事务处理方法,此方法就相当于级联操作public void tranAddFamilyInfo(Employee employee, Spouse spouse, List children) {employeeDAO.insert(employee);if(spouse != null){spouseDAO.insert(spouse);}//child与employee是多对一关系，采用list对象循环处理if (children.size() != 0) {for (int i = 0; i < children.size(); i++) {childDAO.insert((Child) children.get(i));}}}}

 

service中tranAddFamilyInfo就相当于级联操作了，新增employee的同时，如果有spouse和child也同样更新数据库。

至此ibatis的级联操作就结束了。