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}),'%')
SELECT * FROM t_app
<where>
<if test="name != null">
name like CONCAT('%','${name}','%' )
</if>
<if test="url != null">
AND url like CONCAT('%','${url}','%' )
</if>
</where>
limit #{begin},${end}