Mybatis 표현식

+ MyBatis 표현식

- IF
ex) <if test="Content != null">
          명령문...
         </if>
         
         
- choose (when.otherwise)

ex)
<select id="findActiveBlogLike"
     resultType="Blog">
  SELECT * FROM BLOG WHERE state = ‘ACTIVE’
  <choose>
    <when test="title != null">
      명령문 ....
    </when>
    <when test="author != null and author.name != null">
      명령문 ....
    </when>
    <otherwise>
      AND featured = 1
    </otherwise>
  </choose>
</select>



- trim, where ser

ex)
<update id="updateMember" parameterType="dto">
	update tbl_member
	
	<trim prefix="set" suffixOverrides=",">
		<if test = "username != null">username = #{username}.</if>
		<if test = "email != null">email = #{email}.</if>
		<if test = "mp != null">mp = #{mp}.</if>
	</trim>	
		
	set user = ${username}, email = #{email}

	where uid = #{uid}
	
	</update>
	
ex) 연산자

<select id = "empInfo" parameterType="int" resultType="empDto">
   select * from emp
 
 	<trim prefix="where" prefixOverrides="AND | OR">
	 	<if test = "ename !=null"> ename = #{ename}</if>
	 	<if test = "sal" != null>and sal = ${sal}</if>
	 	<if test = "deptno != null> and deptno = #{deptno}</if>
 	</trim>
 </select>



- 반복
ex)
<select id="selectPostIn" resultType="domain.blog.Post">
  SELECT *
  FROM POST P
  WHERE ID in
  <foreach item="item" index="index" collection="list"
      open="(" separator="," close=")">
        #{item}
  </foreach>
</select>

<select>
<![CDATA[     CDATA는 문자라는 뜻 30초과라는 >가 꺽쇠로 인식될수 있다 그걸 방지
select * from dept
where depto > 30;

]]>

<select>
select * from dept
where depto > 30;
</select>