MyBatis_tp50_动态sql_sql标签_抽取可重用的sql片段_使用include标签进行引用

笔记要点
出错分析与总结

 include内部使用自定的属性,之能使用$ {}来取值 ,#{}不能用

工程组织
数据库组织
0.重新修改Bean类
1.定义接口

public interface EmployeeMapper_DynamicSQL {
    //批量插入,测试sql标签
    public void addEmps2(@Param("emps")List<Employee> emps);

2.定义XML映射文件

<!--==================================================-->
    <!--sql标签:
    抽取可重用的sql片段,方便后面的进行引用;
        引用方法:
        <include refid="" ></include> include内部使用自定的属性,之能使用$ {}来取值 ,#{}不能用
    -->
    <sql id="insertColumn">
        <if test="_databaseId=='mysql'">
            last_name ,  email ,gender  ,  d_id
        </if>
    </sql>
    <insert id="addEmps2">
        INSERT INTO tbl_employee(
        <include refid="insertColumn"></include>
        )
        VALUES
        <foreach collection="emps" item="emp" separator=",">
           (#{emp.lastName},#{emp.email},#{emp.gender},#{emp.dept.id})
        </foreach>
    </insert>

3.编写测试代码

@Test
    public void test12() throws Exception {
        SqlSession openSession = getSqlSessionFactory().openSession();
        try {
            System.out.println("++++++++++---- tp48.测试动态sql_ sql标签:可重复引用数据内容");
            EmployeeMapper_DynamicSQL mapper = openSession.getMapper(EmployeeMapper_DynamicSQL.class);
            List<Employee> emps=new ArrayList<>();
            emps.add(new Employee(null,"smith2" ,"smith@qq.com" , "1",
                    new Department(1)));
            emps.add(new Employee(null,"aliex2" ,"aliex@qq.com" , "0",
                    new Department(1)));

            mapper.addEmps2(emps);

            openSession.commit();
        } finally {
            openSession.close();
        }
    }

测试结果

++++++++++---- tp48.测试动态sql_ sql标签:可重复引用数据内容
DEBUG 12-05 18:24:23,805 ==>  Preparing: INSERT INTO tbl_employee( last_name , email ,gender , d_id ) VALUES (?,?,?,?) , (?,?,?,?)   (BaseJdbcLogger.java:145) 
DEBUG 12-05 18:24:23,821 ==> Parameters: smith2(String), smith@qq.com(String), 1(String), 1(Integer), aliex2(String), aliex@qq.com(String), 0(String), 1(Integer)  (BaseJdbcLogger.java:145) 
DEBUG 12-05 18:24:23,821 <==    Updates: 2  (BaseJdbcLogger.java:145)

来源：https://www.cnblogs.com/zhazhaacmer/p/10072585.html

标签

string

sql数据库