[Java] 详解MyBatis模糊查询LIKE的三种方式

public void selectbykeyword(string keyword) {
   string id = "%" + keyword + "%";
   string roletype = "%" + keyword + "%";
   string rolename = "%" + keyword + "%";
   userdao.selectbykeyword(id,rolename,roletype);
 }

list<roleentity> selectbykeyword(@param("id") string id,@param("rolename") string rolename,@param("roletype") string roletype);

<select id="selectbykeyword" parametertype="string" resulttype="com.why.mybatis.entity.roleentity">
  select
    *
  from
    t_role
  where
    role_name like #{rolename}
    or id like #{id}
    or role_type like #{roletype}
  </select>

select
  *
from
  t_role
where
  role_name like '%why%'
or id like '%why%'
or role_type like '%why%';

concat(str1,str2,...)

list<roleentity> selectbykeyword(@param("keyword") string keyword);

<select id="selectbykeyword" parametertype="string" resulttype="com.why.mybatis.entity.roleentity">
  select
  *
  from
  t_role
  where
  role_name like concat('%',#{keyword},'%')
  or
  id like concat('%',#{keyword},'%')
  or
  role_type like concat('%',#{keyword},'%')
</select>

list<roleentity> selectbykeyword(@param("keyword") string keyword);

<select id="selectbykeyword" parametertype="string" resulttype="com.why.mybatis.entity.roleentity">
  <bind name="pattern" value="'%' + keyword + '%'" />
  select
  *
  from
  t_role
  where
  role_name like #{pattern}
  or
  id like #{pattern}
  or
  role_type like #{pattern}
  </select>