mybatis模糊查询拼接查询语句

三种方式：

1.  参数中直接加入%%

　　param.setUsername("%CD%");
      param.setPassword("%11%");

	<select  id="selectPersons" resultType="person" parameterType="person">
		select id,sex,age,username,password from person where true 
			<if test="username!=null"> AND username LIKE #{username}</if>
			<if test="password!=null">AND password LIKE #{password}</if>
	
	</select>

2.  bind标签

<select id="selectPersons" resultType="person" parameterType="person">
  <bind name="pattern" value="'%' + _parameter.username + '%'" />
  select id,sex,age,username,password 
  from person
  where username LIKE #{pattern}
</select>

3. CONCAT

where username LIKE concat(concat('%',#{username}),'%')

4、原样输出$

where username LIKE '%${username}%'