mybatis 动态sql

if:

  

<select id="getEmpsByConditionIf" resultType="com.uban.mybatis.bean.Employee">
 		select * from employee where
 		<if test="id!=null">
 			id=#{id}
 		</if>
 		<if test="name!=null && name!=''">
 			and name =#{name}
 		</if>
 	</select>

trim：字符串截取

choose：分支选择

where：封装查询条件

set：

foreach：

forearch批量插入：

public void addEmps(@Param("employees")List<Employee> employees);

<insert id="addEmps">
 		insert into employee(name,gender,email,d_id) values
 		<foreach collection="employees" item="emp" separator=",">
 			(#{emp.name},#{emp.email},#{emp.gender},#{emp.dept.id})
 		</foreach>
 	</insert>

bind:

sql：抽取重复的sql片段，方便引用 

<sql id="column">
 		id,name,gender,email
 	</sql>
 	
 	<select id="getEmpsByConditionIf" resultType="com.uban.mybatis.bean.Employee">
 		select 
 			<!-- 引用sql标签 -->
			<include refid="column"></include>
		 from employee where