• 單個(gè)查詢

  <select id="selectById" resultType="io.zjh.modules.sys.entity.SysMenuEntity">
  select * from sys_menu t where t.menu_id = #{menuId}
 </select>

• 批量查詢(resultType填返回列表中的類型就行)

 <select id="findMenuName" resultType="java.lang.String" parameterType="java.util.List">
    select menu_name
    from menu
    where menu_id in
  <foreach collection="list" item="valueList" open="(" close=")" separator=",">
    #{valueList}
  </foreach>
</select>

• 單個(gè)插入

<insert id="insert" parameterType="io.zjh.modules.sys.entity.SysMenuEntity">
  insert into sys_menu(menu_id,parent_id,name,url,perms,type,icon,order_num)
  values (
   #{menuId},
   #{parentId},
   #{name},
   #{url},
   #{perms},
   #{type},
   #{icon},
   #{orderNum}
  )
 </insert>

• 批量插入(注意括號(hào)不是寫在open和close)

 <insert id="insertBatch" parameterType="java.util.List">
  insert into sys_role_menu(role_id,menu_id)
  values
  <foreach collection="list" item="item"  index="index" separator=",">
   (
   #{item.roleId},
   #{item.menuId}
   )
  </foreach>
 </insert>

• 單個(gè)更新

 <update id="update" parameterType="io.zjh.modules.sys.entity.SysUserEntity">
  update sys_user
  <set>
   password = #{newPassword}
  </set>
  where user_id = #{userId} and password = #{password}
 </update>

• 批量更新

<update id="updateRoles" parameterType="java.util.List">
  update role
  set enabled = '0'
  where role_id in <foreach collection="list" item="roleIds" index="index" open="(" separator="," close=")"> 
    #{roleIds} 
  </foreach>
</update>

• 單個(gè)刪除

<delete id="deleteByMenuId">
  delete from sys_role_menu where menu_id = #{menuId}
</delete>

• 批量刪除

<delete id="deleteBatchIds"  parameterType="java.util.List">
  delete from sys_user where user_id in
  <foreach collection="list" item="item"  index="index" separator="," open="(" close=")">
   #{item}
  </foreach>
</delete>

傳入list和array比較

• 如果傳入的是單參數(shù)且參數(shù)類型是一個(gè)List的時(shí)候梯嗽，parameterType為java.util.List房蝉。collection屬性值為list
  int deleteByLogic(List list);
• 如果傳入的是單參數(shù)且參數(shù)類型是一個(gè)array數(shù)組的時(shí)候， 參數(shù)類型為parameterType="int" 集合 collection的屬性值為array 。
  int deleteByLogic(int[] array);

<foreach item="item" collection="array" open="(" separator="," close=")">
            #{item}
</foreach>

jdbcType

• 有時(shí)候插入更新時(shí)需要制定這個(gè)類型，是因?yàn)閭魅肓丝罩担瑹o法判斷它的類型,mybatis會(huì)報(bào)錯(cuò)腺劣。