Day31——MyBatis动态SQL foreach

小灰灰 2023-07-04 15:39 1阅读 0赞

# 一. 例子 #

EmployeeMapperDynamicSQL.java

package com.atguigu.mybatis.dao;
    
    import java.util.List;
    
    import org.apache.ibatis.annotations.Param;
    
    import com.atguigu.mybatis.beans.Employee;
    
    public interface EmployeeMapperDynamicSQL { 
    
    	public List<Employee> selectEmployeeByIds(@Param("ids")List<Integer> ids);
    }

EmployeeMapperDynamicSQL.xml

<select id="selectEmployeeByIds" resultType="com.atguigu.mybatis.beans.Employee">
    	     
    	      select id, last_name, email, gender from tbl_employee
    	      where id in 
    	         <foreach collection="ids" item="currId" open="(" close=")" separator=",">
    	             #{currId}
    	         </foreach>
    	</select>

TestMyBatisDynamicSQL.java

@Test
    	public void testForeach() throws Exception{ 
    		SqlSessionFactory ssf = getSqlSessionFactory();
    		SqlSession session = ssf.openSession();
    		try { 
    			EmployeeMapperDynamicSQL mapper = session.getMapper(EmployeeMapperDynamicSQL.class);
    			List<Integer> ids = new ArrayList<>();
    			ids.add(1001);
    			ids.add(1005);
    			ids.add(1006);
    			
                List<Employee> emps = mapper.selectEmployeeByIds(ids);
                System.out.println(emps);
    			
    			
    			session.commit();
    		} finally { 
    			// TODO: handle finally clause
    			session.close();
    		}
    		
    	}
    
    public SqlSessionFactory getSqlSessionFactory() throws Exception { 
    		String resource = "mybatis-config.xml"; 
    		InputStream inputStream = 
    				Resources.getResourceAsStream(resource); 
    		SqlSessionFactory sqlSessionFactory = 
    				new SqlSessionFactoryBuilder().build(inputStream);
    		return sqlSessionFactory;
    	}